More on thefontanels.

Justin W.: Iseach human brain unique and if so, how unique are they from other human brains?

Answer: Yes, each brain is unique.

1. Brains are unique in physical appearance. No two brains haveexactly the same outside appearance. The patterns of sulci and gyri(bumps and grooves) will make each brain look different from another.

2. Each brain will have a different number of cells. Neurons probablydie at different rates in different people.

3. Each person has different experiences and each brain holds uniquememories. This implies that the physical structure that holds thesememories must be different.

4. Every person has different behaviors and different experiences.Differences in the brain are responsible for all of these.

5. (From Neuroscientist Network member, Dr. Pat F.): Though the generalcircuits and connections among different parts of the brain will be fairlycommon among different brains, the specific connections in regard to theneurons and number of connections with each neuron will be verydifferent for each individual, and can even change over the life of the person.

6. (From Neuroscientist Network member, Dr. Kevin L.): the apparentvariation in the nervous system on the molecular level is large as well. Differences in receptor distributions, neurotransmitter and neurohomonelevels and perhaps even cell adhesion molecules may all contribute tothe individuality of each brain and person!

I am sure you can think of more differences between brains.

Lee: Doblind people dream?

Answer: Everyone dreams. Even the blind have"desynchronized sleep". However, during this "dream sleep" stage, peoplewho are blind from birth do not show the rapid eye movements that sightedpeople have. Also, blind people have dreams that are primarily auditory,tactile or even involve taste and smell. Three scientific papers thatdiscuss dreams in the blind:

• The structure of laboratory dream reports in blind and sightedsubjects
• Symbolism in the dreams of the blind
• Emotions in the dreams of the blind

Kel: How doesProzac work in the brain?

Answer: Prozac is a "selective serotonin reuptakeinhibitor". This means that it prevents the neurotransmitter called serotonin from being taken back up into the presynapticaxonal terminal. Therefore, serotonin will stay in the synaptic cleft andwork for a longer time.

For more on prozac, see:

• http://www.prozac.com/
• http://www.mentalhealth.com/drug/p30-p05.html

Jim C.: Withall the money the pharmaceutical companies are pouring into treatingeverything from impotency to toenail fungus, is anyone trying to create abetter general anaesthestic agent? What would be the characteristics ofyour "dream" gas?

Answer (By Dr. Chris B., member of the NeuroscientistNetwork): Certainly work is underway at multiple pharmaceuticalcompanies to develop improved anesthetic gasses. However, the amount ofeffort, i.e., money, expended is tempered by the fact that the number ofpeople who receive these drugs is far less than the number who mightbenefit from drugs to treat toenail fungus or impotence. Consequently,the potential financial return is nowhere near as great, and thesecompanies, like all companies, are in the job of making money for theirowners (shareholders).

Now, as to the ideal anesthetic gas. The properties that would be desiredare these:

1. Rapid onset of effect and equally rapid offset so that patients go tosleep quickly and wake up quickly.

2. No unwanted side effects like cardiovascular depression (manifest aslow blood pressure), irritation of air passages, organ toxicity (somedrugs used in the past and some still in use today can cause liver andkidney damage in some situations).

3. Very potent so that you need to use very little. This is importantbecause the more anesthetic gas you need to give the less oxygen you cangive.

4. Odorless, for patient comfort.

5. Nonflammable so that there is no risk of explosion when usingelectrical equipment in the operating room. This is one of the reasonswe no longer use ether.

6. Inexpensive

Pam S.: Isthere any part of the brain that starts with the letter "z"?

Answer: Yes! An area of the brain that startswith the letter "z" is the "zona incerta".

Kim F.: Whatanniversary falls on September 13, 1998 and why is this an important eventin the history of brain science?

Answer: September 13, 1998 marks the 150thanniversary of the date that Mr. Phineas Gage was shot through the headwith an iron tamping rod. His injury and the resulting behavioral changesthat he developed gave scientists information about the role of thefrontal cortex.

For more on Phineas Gage, see lobes of thebrain.

Alicia E.: Isaw a program on A&E about a theory that zombies were really an accidentof poison. The poison was traced back to the puffer fish. A poisoncalled tetrodotoxin. Do you have any more information on tetrodotoxin?

Answer: Yes, I have heard of the zombie/poisontheory before. Tetrodotoxin is a poison from the pufferfish and itsaction is to block sodium channels in nerve cells.

For more on tetrodotoxin, please see:

• http://faculty.washington.edu/chudler/toxin1.html
• http://vm.cfsan.fda.gov/~mow/tet.html
• http://vm.cfsan.fda.gov/~mow/chap39.html
• http://www.macalester.edu/~psych/whathap/diaries/diariess98/tal/tetro.html
• http://www.emedicine.com/emerg/topic576.htm
• http://www.icnpharm.com/biomed/msds/english/158998ms.htm
• http://itssrv1.ucsf.edu/~adcom/listserv/ucsfnews/0086.html

Erin C.: Arethe cranial nerves part of the central nervous system or peripheralnervous system?

Answer: The cranial nerves are part of the peripheral nervous system.

Tami: Doinfants dream?

Answer: Most probably, the answer is "Yes, infantsDO dream." I say most probably, because the only way to be 100% surethat someone has dreams is to ask if he or she dreams.

As you may know, dreaming occurs in the phase of sleep called "Rapid EyeMovement" (REM) sleep. Most of the time if people are awakened during REMsleep, they will say that they were dreaming. Infants spend MORE time inREM sleep compared to adults. Therefore, although infants cannot actuallytell you that they dream or not, it is likely that they spend more time dreaming than adults.

For more on sleep and dreaming, see:
http://faculty.washington.edu/chudler/sleep.html

J. Sil:Arethere any animals that have ultraviolet and infrared vision?

Answer: Some snakes and fish can see infraredwavelengths of light. The bee and butterfly can see in the ultravioletrange.

For information on bee and butterfly vision, see:

http://scholastic.com/Magicschoolbus/games/whatsee/responses0798.htm
http://vertigo.derby.ac.uk/BiologicalImaging/Shows/fys97/Eddie/bvision.html

For more on the sensory abilities of animals, see Amazing AnimalSenses.

Lizzy: Whatcauses "Brain Freeze?"

Answer: No one is really sure what causes brainfreeze but there are a few theories. "Brain Freeze", also called an "icecream headache", is thoughtto be caused by rapid cooling of the palate (upper part of mouth) whichthen activates nerve fibers that cause pain. Rapid cooling may affect blood vessels which change shape. This change in shape may activate nervefibers that cause pain.

For more on Brain Freeze, see:

• http://www.bmj.com/cgi/content/full/314/7091/1364
• http://cgi.pathfinder.com/drweil/archiveqa/1,2283,1027,00.html

J.S.: What is all this about nerve cells growing in adult human brains? I thoughtneurons did not grow in adult brains.

Answer: Recent experiments in humans have shownthat new neurons DO grow in at least one area of the brain (thehippocampus). For more on this topic read the page called

Sarah: Do youhave any information on the manatee's nervous system.

Answer: You are in luck. There is an excellentweb site about the manatee brain at:

Mike B.:What is PTC paper? Why do only certain people taste it?

Answer: PTC paper contains a chemical called"Phenolthiocarbamide."

For about 70% of the people in the U.S., the PTC paper tastes very bitter.The other 30% of the people say it just tastes like paper.

This ability to taste this material is genetic. The gene for tasting thechemical is DOMINANT over the one for not tasting it. For an experimentthat describes the use of PTC paper, see:

http://www.col-ed.org/cur/sci/sci83.txt

Rolf: I wasdoing some research a few days ago and found some info and a .gif file ofthe first recorded EEG. Unfortunately I did not bookmark thepage. Do you know where this might be located?

Answer: The page you are looking for may bethe one located at:

Gavin: What is a reflex arc? The type involved when you touch a hot surface and thenpull away.

Answer: The reflex arc is a concept related tomuscle reflexes. The arc is made up of 1) an afferent neuron that detectsa stimulus; 2) a central processor and 3) an efferent neuron that controlsa muscle.

A reflex arc that has only a single synapse (between the afferent andefferent neuron) is called a monosynaptic reflex.The kneejerk reflex is a monosynaptic reflex.

A reflex arc with multiple synapses between the afferent and efferentneurons is called a polysynaptic reflex. Limbwithdrawal to a painful stimulus (flexion reflex), like in your example,is a type of polysynaptic response.

Here is the basic pathway of the flexion reflex for the foot:

1. Painful stimulus sends a message to the spinal cord where theperipheral nerve fiber (neuron #1) synapses (Synapse #1).

2. Neuron (#2) in the spinal cord (an interneuron) projects to anotherneuron (#3) in the spinal cord (Synapse #2).

3. Neuron #3 in some cases cross over to the other side of thespinal cord; some neuron #3 stay on the same side. They all synapse on a motorneurons (#4).

4. The motor neuron sends an axon to muscles. On the side of the body thatis the same as the stimulus, the result of the motor neuron is EXCITATIONof the flexor muscles and INHIBITION of the extensor muscle. On the sideof the body opposite to the stimulus, the result is EXCITATION of theextensor muscle and INHIBITION of the flexor muscle.

5. The result of this circuitry to the flex (withdraw) the painful limband to extend the opposite leg for support.

It should also be mentioned that this reflex can be modified by signalsfrom the brain. A diagram of this reflex arc is the best way to visualizethis circuitry. Try to draw it out yourself.

Kate: How isthe reflex pathway organized so that when light is shined in one eye thepupil in the other eye constricts?

Answer: Light into one eye causes pupilconstriction of this same eye (direct response) as well as in the othereye (consensual response). Retinal ganglion cells that project to thepretectal area of the brain are responsible for these reflexes. Neurons inthe pretectal area project to the Edinger-Westphal nucleus on BOTH SIDESof the brain. Neurons from the Edinger-Westphal nucleus on each side ofthe brain then project to the ciliary ganglion. The Edinger-Westphalnucleus on the right side projects to the ciliary ganglion on the rightside and the Edinger-Westphal nucleus on the left side projects theciliary ganglion on the left side. The ganglia then send axons to themuscle that controls pupil size.

Aaron: I waswatching a segment on television about Human Growth Hormone (HGH),asubstance naturally produced by the brain. Do artificial supplements ofHGH really relieve the effects of aging on the brain? What are possibleside effects?

Answer: The TV show on human growth hormone thatyou watched could have been the ABC 20/20 program. On September 25, 1998,they aired a program titled "The Fountain of Youth? Human Growth HormoneMiracle Drug or Risky Fad?". You can even read the transcripts of this show that present the pros and cons ofthis controversial treatment.

It is my understanding that the FDA has approved Human Growth Hormonefor people who are deficient in this hormone produced by thepituitary. However, its use in normal, health people, as an anti-agingtreatment is not approved. A quick search on the Internet will turn upmany companies willing to sell you this product, but purchasing humangrowth hormone may not be worth your money.

The National Institute on Aging atthe National Institutes of Health has asummary of some of these controversial treatments for aging on anexcellent page titled "Pills, Patches, andShots: Can Hormones Prevent Aging?". This paper discusses some of thepossible side effects of human growth hormone: diabetes, high bloodpressure and heart failure, joint pain and carpal tunnel syndrome.

Aaron: I havebeen wondering for some time on the neurological effects ofelectromagnetic fields, and if there is any explanation as to why thereare high incidents of brain tumors in towns located near powerstations.

Answer: The correlation between electromagneticfields and brain cancer is somewhat inconclusive. Some studies show acorrelation, others do not. I will direct you to a few resources whereyou can read up on this subject and you can come to your ownconclusions.

1. Qand A about EMF
2. EMF Information
3. EMFScience Review
4. CancerFacts

D.S.: Do you the refractivevalues of the cornea and the aqueous humor?

Answer: According to http://www.unb.ca/physics/1940/HumanEye.fm.htm, the refractive indexof the cornea = 1.376

According tohttp://retina.anatomy.upenn.edu/~lance/eye/humor_aqueous.html, therefractive index of the aqueous humor is either 1.3374 or 1.336.

Douglas B.:I recently observed a craniotomy and a rather important question popped up: How does the surgeon distinguish normal brain tissue from harmfultumor tissue?

Answer (By Dr. John L., neurosurgeon): There areseveral answers to this question. The first is that a tumor often looks different from normal brain and the surgeon can be guided byappearance. Second, the location of the tumor can be fairly well knownbased upon imaging studies such as MR (magnetic resonance imaging) or CT(computer tomography). By studying the relation of the tumor to identifiedstructures (blood vessels, major sulci, etc), it is possible to have agood idea of where the tumor lies. Third, one can use intraoperativeultrasound to locate the tumor, as its sound reflective characteristicsare different from the brain. Fourth, certain types of tumors areencapsulated and the boundary is quite discrete. Oher types of tumors areinfiltrative and the boundaries are not discrete. When the tumor is insilent parts of the brain, one can deliberately take out surroundingtissue so as to get an adequate margin. However, the big problem withintrinsic gliomas is that they have no discrete boundaries and are widelyspread through the brain before they produce any symptoms. This is whythey cannot usually be cured. The tumor cells literally swim therough thebrain and eventually grow to produce a recurrence.

Mik:Who discovered ribosomes?

Answer (By Neuroscientist Network Members, Dr. M.B. andDr. Doug R.): Ribosomes, which means "body of ribose" after theseorganelles were found to contain the sugar ribose, were first described byAlbert Claude in 1938 and were observed in animal cells which had beeninfected with Rous sarcoma virus. He then ascertained that noninfectedcells also contained these particles and first called them microsomes(which in part they were, because ribosomes are bound to microsomes) Inbacterial cells they were first described by Luria, Delbruck and Andersonin 1943.

George Palade and Keith Porter also described them around 1950 using EMwhen they were at Rockefeller Institute (part of reason for Palade's Nobelprize in 1974), and noticed their location on the endoplasmic reticulum(RE & RER named and disc by Porter) and free in cytoplasm.

Jill: I am wondering what kind ofjobs are available for students who graduate with a Master's inNeuroscience? I am also looking for a good reference of biotechnologycompanies in the NorthWest.

Answer: There are some schools that offer aMaster's degree in Neuroscience, but many will not admit students unlessthey are committed to obtaining a Ph.D. There are many job opportunitiesfor people with a Master's degree:

• Industry - in such areas as product development and quality controlScience journalism - for books, magazines or textbooks
• Teaching - it may be possible to teach at the community college level, but most teaching jobs at 4 year universities go to those people with a Ph.D. It may also be possible to get a high school teaching certificate with some additional training.
• Laboratory work - skilled technical help is always needed in researchlaboratories

The Pacific Northwest is a very active area for biotechnology companies.Here are a few places to give you more information such companies andabout the industry:

1. http://www.wabio.com/3.asp
2. http://www.psbs.org/html/psbs2.htm
3. http://biotech.chem.indiana.edu/
4. http://www.biospace.com/
5. Immunex
6. http://seaccd.sccd.ctc.edu/~sporte/companies.html

Jim: I heardon the radio that the brain is over 50% fat. Any truth to this? Also, isthis where the term 'fat head' comes from?

Answer: I think the 50% number is a bit of anexaggeration. According to some numbers that I have found in theliterature, the brain is composed of the following components:

Water                78%Lipids               10%Protein               8%Carbohydrate          1%Inorganic salts       1%Other                 2%

Lipids are the "fats". I suppose if you ignoredthe water, then lipids would be slightly less than 50% of the remainingmaterial, but I don't think this is a fair way to manipulate thenumbers.

There are 3 types of brain lipids: cholesterol, glycerophospolipids andsphinoglipids. Myelin, which is the insulation around the axons ofneurons, is about 80% lipid.

I am not sure where the expression "Fat Head" came from. Actually, if youknow how important fats (lipids) are to the brain and rest of the nervoussystem, you would NOT take this expression as an insult. Fats areESSENTIAL for the proper function and development of the brain. Isuspect the expression "Fat Head" has NOTHING to do with the fat (lipid)content of the brain.

Michael S.:Can pure alcohol (ethanol, the kind you can drink) be absorbed through theskin and cause intoxication?

Answer: Ethyl alcohol (ethanol) is not absorbedthrough the skin very well. According to Goodman and Gilman's, ThePharmacological Basis of Therapeutics, 1985, p. 378:

"Absorption of alcohol through the human skin is negligible."

However, there are a few cases in the literature of intoxication caused byskin absorption of alcohol in INFANTS and YOUNG CHILDREN. One caseinvolved a 1 month old infant who had her umbilical cord stump soaked ingauze pads containing ethanol. There are other reports of ethanolpoisoning in children who had alcohol-soaked gauze pads applied to theirskin in attempts to relieve abdominal pain. Intoxication may also occurafter breathing in alcohol vapors since alcohol can be absorbed throughthe lungs.

E.F.: Mightyou be able to get some idea of how many neurons in the brain arefiring by EEG? It seems one could compare an actual EEG measurement toa hypothetical maximum value given by: (# of neurons in brain) X(estimated current created by single action potential).

I thought your language on the 10%myth page as a bit misleading here: "Even if neurons arenot firing action potentials". Neurons don't "fire" action potentials;the firing IS the action potential. I also take issue with yourstatement that non-firing neurons may still be receiving signals fromother neurons. With an exception or two that I can think of(inhibition), neuronal function is an all-or-none phenomenon. Neuronsare either firing in response to a stimuli, or they aren't. If theneuron doesn't fire, the stimuli isn't important.

Answer: Let me clear up some misinformation thatyou have. First, an estimation of the number of neurons in the brain thatare firing by using the EEG will NOT be accurate. The EEG does NOTnecessarily measure action potentials! Rather, the EEG is the averagedactivity of thousands of neurons, some of which are not firing actionpotentials. This activity may be generated by postsynaptic potentials.This relates to your second comment.

You are right...firing of an action potential is what neurons do. It isONE thing that neurons do, but NOT the only thing. Non-firing neuronsreceive thousands of signals from other neurons. These signals do NOTalways cause an action potential! An action potential will only begenerated if the neuron is depolarized above its threshold. Neuronalfunction is NOT all-or-none! Action potential firing IS all-or-none. The"decision" to fire an action potential is NOT all-or-none; it isbased on the summation of many smaller responses (the excitatory andinhibitory postsynaptic potentials).

Furthermore, it is incorrect to state that just because a stimulus doesnot cause an action potential to fire it is not important. It may be partof a complex response that results in other neuronal processes (includinga postsynaptic response). It may depolarize a neuron such that otherpostsynaptic responses cause the neuron the fire.

More on theaction potential.

G.H.: Willhaving a seizure hurt the brain or destroy brain cells?

Answer (By Dr. Chris B., member of the NeuroscientistNetwork): Seizures can damage brain cells if they are prolonged(15-20 minutes is a number I remember being taught but I do not have aprimary reference) because oxygen/glucose needs can exceed supply. Also, excitatory neurotransmitters released during seizures can be injurious ifthe seizure is prolonged. However, most seizures are not prolonged and donot cause damage.

Tera S.:Why do you see "stars" after you are bumped and sometimes after asneeze or a cough?

Answer (By Dr. David P., member of the NeuroscientistNetwork): The "stars" are a result of a mechanicalstimulation of the normally light-stimulated rods and cones in the retina.Rather than the light uncoupling rhodopsin to opsin and retinal, the bumpuncouples them mechanically. Pressure caused by a sneeze or cough canalso mechanically stimulate the photoreceptors. The final result is that"light spots" are seen.

Afri B.: What is sleeping gas made of?

Answer (By Dr. Chris B., member of the NeuroscientistNetwork): There are multiple gases that have been used forproducing generalanesthesia, including chloroform, ether, cyclopropane, enflurane,isoflurane, halothane, desflurane, and most recently sevoflurane. Thelast four drugs are the only ones still in use in the United States. Thesedrugs are all relatively small molecules in a class called "halogenatedhydrocarbons." Their basic structure is that of 1 or more carbon atomsconnected to each other as well as to one or more halogen atoms (chlorine,flourine, or bromine) and with some drugs an oxygen molecule as well. Theproperty that all of these drugs have in common is that they easilydissolve in the membranes of cells and reversibly alter their function.In particular, current evidence suggests that these drugs act on neuronsin the brain to increase how tightly the neuron binds to aneurotransmitter called GABA. This neurotransmitter is responsible forinhibiting the activity of other neurons. Interestingly, other drugs likevalium and perhaps alcohol have a similar mechanism.

Incidentally, most of these drugs are not gases at room temperature, theyare liquids. But they evaporate very rapidly (just like rubbing alcoholor acetone (fingernail polish remover) to become gasses. Thus, to usethese drugs they must be placed in a device called a vaporizer. Oxygen isthen bubbled the liquid. The oxygen picks up some of the liquid andcarries it away as a gas.

Tara A.: I would appreciate it if you could recommend some useful texts that I couldrefer to for further information on the field of neuroscience.

Answer: The ones I like are:

1. Principles of Neural Science, 3rd edition, edited byE.R. Kandel, J.H. Schwartz and T.M. Jessel, Norwalk: Appleton and Lange,1991. This is one of the best textbooks available. A shortened versionof this text is also available:
   Essentials of Neural Science andBehavior, edited by E.R. Kandel, J.H. Schwartz and T.M. Jessel,Norwalk: Appleton and Lange, 1995.

2. Neuroscience: Exploring the Brain, by M.F. Bear, B.W.Connors and M.A. Paradiso, Baltimore: Williams and Williams, 1996.

3. Neurobiology, 3rd edition, by G.M. Shepherd, New York:Oxford Univ. Press, 1994.

4. Neuroscience, edited by D. Purves, G.J. Augustine, D.Fitzpatrick, L.C. Katz, A.S. LaMantia and J.O. McNamara, Sunderland:Sinauer Asso., Inc., 1997.

5. Physiology of Behavior, 6th edition, by N.R.Carlson, Boston: Allyn and Bacon, 1998.

6. The human brain : an introduction to its functionalanatomy, by J. Nolte, St. Louis, MO, Mosby, 1999.

Yi W.: I wouldlike to know what is the cause of blindness? Can it happen after birth?Can watching too much T.V., using the computer too much, and reading indim light for a long time result in blindness?

Answer: Of course an accident that damages theeyes can cause blindness. Blindness can also be caused by brain damageafter a "stroke".However, according to the National Federation of theBlind, the major causes of blindness in the UnitedStates are:

1. Cataracts
2. Diabeticretinopathy
3. Glaucoma
4. MacularDegeneration
5. RetinitisPigmentosa

Blindness occurs more frequently in older people,but can happen in children too.

The American Academy of Ophthalmology, American OptometricAssociation, Massachusetts Commissionfor the Blind and "PreventBlindness America" all agree that watching too much T.V., using thecomputer too much, and reading in dim light for a long time do NOT causeblindness or damage the eyes. However, reading in good light will make iteasier to read and will prevent eye strain and fatigue.

A. Sita: Canyou tell me what deja vu is and the areas of the brain that are importantfor it or where I can find this information? I have spent hours searchingwith little luck.

Answer: Deja vu is the perception that a current"event" has happened in the past. There has not been too much research on themisunderstood topic of deja vu, but there are numerous cases of peoplewith "temporal epilepsy" that experience sensations of deja vu. Also,electrical stimulation of the temporal lobe may also cause deja vufeelings.

Deja vu is very difficult to study for several reasons. First, there areno animal models by which to study this phenomenon. Second, it is verydifficult to cause feelings of deja vu and it is very difficult to studydeja vu in a controlled laboratory situation. Furthermore, it may be thatthe mechanisms of deja vu in normal people are different than those inpeople with epilepsy.

It appears that there may be psychological factors (for example, stress)that may precipitate deja vu experiences. However, deja vu does not seemto be uncommon, and it alone should not be taken as a sign of disease. For more information, see the following web pages:

• http://dcn.davis.ca.us/~btcarrol/skeptic/dejavu.html
• http://www.cmhc.com/perspectives/articles/art03965.htm
• http://ego.psy.flinders.edu.au/webpages/learning/byatlwco/page4.html
• http://mcns10.med.nyu.edu/cases/temporalsub/sub.html
• http://www.co.broward.fl.us/mei00216.htm

For even more information on deja vu, you might want to track down thefollowing papers (here are the abstracts):

• Dreamy states and psychoses in temporal lobe epilepsy: mediating role ofaffect.
• Thedeja vu experience: remembrance of things past?
• Anatomical origin of deja vu and vivid 'memories' in human temporal lobeepilepsy.
• Mental phenomena induced by stimulation in the limbic system.
• Themechanism of deja vu.

Linda F.: Arecent episode of the TV show "The X-Files" had to do with ESP and AgentMolder mentioned a part of the brain that scientists still are not surewhat it is used for. He called it "The God Center". Could you give mesome information about this section of the brain and what it does.

Answer: So that's why I have been getting "GodCenter" questions recently! Thanks for telling me this. I don't watchthe X-Files. You can tell your students not to believe everything theysee on TV (or read in popular magazines).

With regard to the "God Center" of the brain....there are many areas ofthe brain that are involved in higher cognitive functions including thebelief in God. I do not think there is one particular area of thebrain that scientists can point to that would indicate where this islocated. Many higher functions have multiple areas that areimportant...for example, memory is located in many different parts of thebrain - there is NO "center". This is probably true for religiousbelief.

However, there was a study presented at the 1997 Society for Neurosciencemeeting titled "The neural basis of religious experience". Theseresearchers mention the temporal lobe and the amygdala as possible areasof the brain important in the belief in God and religion. There are alsoforms of epilepsy that cause patients to have feelings of a religiousexperience. Nevertheless, these areas of the brain are only PART of thewhole story...these areas are probably part of a much larger "circuit".

(A good reference on this topic is: J.L. Saver and J. Rabin, The NeuralSubstrates of Religious Experience, Journal of Neuropsychiatry, 9:498-510,1997.)

A.K.: I havehad to undergo 4 major surgeries within the last year, 3 of which used general anesthesia. Has research determined if there are lingeringeffects on the brain? I find that I am forgetful for quite awhile aftereach surgery and the longer the surgery, the longer the forgetfulness. Does the anesthesia's effect on the brain cause the body to involuntarilytwitch while at rest? This is also something I have found occurring aftera general and it continues for quite some time. I would like to researchthis further.

Answer (By Dr. Chris B., member of the NeuroscientistNetwork): Several issues are relevant to your questions:

1. Mental function: First, it is important to realize that anesthesiadoes not occur in a vacuum, thus it is difficult to separate the effectsof anesthesia from those of the surgery. For example, the "tissue injury"caused by surgery results in the release of many compounds (e.g.,cytokines, leukotrienes, prostaglandins, etc.) that may affect the way wefeel. Second, most people require pain medications after surgery andthese drugs also have potent effects on mental function. Finally, somesurgical procedures have been shown to produce brain injury with somefrequency(e.g., heart surgery which requires bypass and carotid arterysurgery).

However, in studies done on volunteers who had anesthesia but not surgery,normal mental function as measured by sophisticated neurobehavioraltesting recovers within a few hours.

2. Twitching: General anesthetics inhibit inhibitory neurons in thespinal cord and brain even at relatively low concentrations. As a result,spinal reflexes are a little overactive in the first hours after surgery.A classic example of this is the fact that patients exhibit marked clonus(involuntary bouncing of the foot when the Achilles tendon is stretched)early in the recovery from general anesthesia. Since clonus is a sign ofbrain injury, it is possible that physicians may be unaware of the impactof anesthesia on clonus and think that the patient had suffered a braininjury. This is a long way of saying that muscle twitching afteranesthesia that persists for a few hours is not surprising and is in factnormal. However, keep in mind that many drugs as well as bed rest cancausing muscle twitching, thus cause is not always clear.

Nancy L.: Howmany neurons are in an insect brain?

Answer: I do not know the number of neurons inthe brain of every type of insect, but I hope the number of neurons in thebrain of a bee, fly and locust will help.

# of neurons in worker bee brain = 851,458
# of neurons in drone bee brain = 1,209,681
# of neurons in fly brain = 337,856
# of neurons in locust brain = 360,000

Remember, it has been estimated that the humanbrain has 100,000,000,000neurons.

Reference for the number of neurons in the insect brainsis: Comprehensive Insect Physiology, Biochemistry and Pharmacology,Vol. 5, edited by G.A. Kerkut and L.I. Gilbert, Pergamon Press, Oxford,1985, p. 307.

Alex F.:How many messages are sent through an average human body in one day?

Answer: First, let me say that my answer will bean estimation only. There really isn't a fixed number of messages or actionpotentials that happen each day.

Second, I will make three big assumptions:

1. we will talk about the brain only
2. we will assume that the brain has 100,000,000,000 (100 billion) nervecells (also called neurons).
3. we will assume that each neuron will fire at a rate of 1 everysecond.

So, 100 billion neurons firing at one per sec for 60 sec = 100 billion X 1/sec X 60 sec = 6,000,000,000,000 (6 trillion perminute)

Then, 6,000,000,000,000/min X 60 min/1 hr = 360,000,000,000,000 (360trillion per hour)

360 trillion X 24 hours = 8,640,000,000,000,000per day (8.6 quadrillion per day)

That's quite a lot!!!! You can check my math yourself.

Frank: How didparts of the brain get their names?

Answer: Many brain structures are named for whatthey actually look like. Greek and Latin words are usually used. Forexample, an area of the brain that is important for memory is called thehippocampus. In Greek, hippocampus means "sea horse". The structure wasnamed hippocampus because it looked like a sea horse. Another example isa nerve called the vagus nerve. In Latin, "Vagus" means "wandering". So,the vagus nerve gets its name because it "wanders" around the body. Ifyou are interested in learning about more names of brain structures, seemy page about the origin of brain structure names at:

http://faculty.washington.edu/chudler/neuroroot.html

Jody: Wouldyou have any good books you could suggest that would be good for parents of preschooler to read?

Answer: I have a list of books that should suityour purpose at the bottom of the on-line and off-linebooks and articles page. You will have to either click on the"off-line books" button or scroll all the way to the bottom of this pageto get to the books (and videos). Most of these books should be in a goodpublic library system. Two books that I highly recommend are:

1. Susan A. Greenfield, The Human Mind Explained, Henry Holt and Co.,New York, 1996, pp.192. An EXCELLENT guide to the brain with plenty ofpictures.
2. Anne D. Novitt-Moreno, How Your Brain Works, Ziff-Davis Press,Emeryville, 1995, pp. 170 .

Mari C.: Whoare some of the famous people who have (or had) epilepsy?

Answer: According to the Florida Epilepsy ServiceProviders, the following people had epilepsy:

• Writers: Lord Byron, Edward Lear, FeodorDostoevsky, Gustave Flaubert, Charles Dickens, Agatha Christie, VachelLindsay, Truman Capote

• Statesmen: Napoleon Bonaparte, Alexander theGreat, Julius Caesar, Peter the Great

• Philosophers: Socrates, Pythagoras

• Artists: Vincent van Gogh, Leonardo da Vinci,Michelangelo

• Composers: Peter Tchaikovsky, Georg FreidrichHandel

Jake C.: When a nerve sends apain message, does it injure the nerve.

Answer: No, a nerve is NOT usually injured when itsends a pain message. This is the normal function of some nerves. Anociceptor is a receptor for stimuli that are painful. Signals from anociceptor are sent through nerves to the spinal cord. The actualtransmission of this signal does not damage the nerve. However, sometimesthe SKIN and the receptor can be injured when something painful hashappened like when the skin is burned severely. One more thing - IF anerve is injured, for example by an accident that crushes or cuts anerve, then an abnormal pain message will sometimes be sent to the centralnervous system. When this happens even after a wound is healed, itcan sometimes cause "chronic pain" conditions.

Sharyn H.: Has the study by Gould & McEwen which was written up in the New York Times,about the growth of new brain cells been published yet?

Answer: Yes, this paper has been published: E. Gould, P. Tanapat, B.S. McEwen, G. Glugge and E. Fuchs, Proliferation ofgranule cell precursors in the dentate gyrus of adult monkeys isdiminished by stress, Proc. Natl. Acad. Sci., vol. 95, pp. 3168-3171,1998.

These researchers found that new neurons (granule cell type neurons) areadded to the hippocampus in adult marmosets. Marmosets are new world primates. The addition of new neurons to the hippocampus has already beendemonstrated to occur in rats and tree shrews. Stress reduced the numberof new neurons. Whether these findings occur in old world primates (likerhesus monkeys) and humans remains to be determined.

What this means with regard to memory and learning is unknown at thistime. The hippocampus is thought to play a role in the consolidation ortransfer of short-term memories to long-term memory. However, how theaddition of new neurons in the hippocampus is involved in this process isunknown. It is clear though that one of the "facts" that is always taughtand that is in most textbooks, that "the number of neurons in the brain isfixed at birth", is most likely false. I think that this type of researchmay lead to the possible discovery of methods and techniques to grow newbrain cells after injury (e.g., stroke) and repair damage to thebrain and spinal cord.

^Update A new study published in theNovember 1998 issue of Nature Medicine describes data that showthe development of NEW NEURONS in the hippocampus of adult humans!

Kelly A.: I amcurrently in an Anatomy course covering nerves. The instructor explained that he was told of a nerve in or near the ear thatis known as the Roman Nerve - apparently applying pressure to it causesvomiting so was utilized by the ancient Romans during their gluttonousfestival to allow for further ingestion. Do you have any additionalinfo on this - perhaps the "real" name of the nerve and its location??

Answer (By Dr. Joel G., member of the NeuroscientistNetwork): According to our best resident anatomist, you're talkingabout the auricular branch of the vagus nerve (the tenth cranial nerve). Most of the vagus nerve innervates visceral organs, providing reflexivecontrol mechanisms, but this one branch innervates the eardrum. It likelysends signals to nucleus solitarius -- which gets other vagus nerve input-- and which plays some role in regulating gut reflexes. This anatomisthad heard that all it required was a tickling of the eardrum with afeather (but neither of us have tried it!) Just why this little branch ofthe vagus nerve goes to the eardrum is a hard question to answer.

Russell A.:If you took all the blood vessels of an average adult and laid them outhow long a line would they form?

Answer: This is not exactly a neurosciencequestion, but it is interesting. According to The Franklin InstitutePage on the Heart, the total lengthof all the blood vessels of the average adult is: 100,000 miles long!!By the way, the average length of all the blood vessels in a child is60,000 miles long.

Brian G.:I am doing a project on neurons and I would like to know how are neuronsdifferent from each other.

Answer: Many people assume that all neurons arealike, but this just is not true. There are many differences betweenneurons.

I will divide this differences into structural (anatomical) differencesand functional (physiological) differences.

Structural Differences

1. The shape of neurons can be different. Neurons can be divided intoseveral main types: multipolar, unipolar and bipolar types of neurons.This separation refers to how many processes (dendrites and axon) eachneuron has...a multipolar neuron has many dendrites, a unipolar andbipolar neuron has few. These types of neurons are described in moredetail on my page on cell types. Neurons have been classified even further by giving them names based onwhat they look like...for example, basket cells, granule cells, pyramidalneurons, etc.
2. The size of the cell body (soma) of each neuron can be different. Thediameter of a cell body can be very small (less than 10 microns) or large(about 100 microns).
3. The number of synapses a neuron makes can be small or very large(more than 1,000).
4. The number of synapses a neuron receives can be small orlarge.
5. The diameter of the axon of neurons can be different.
6. The type of synapse a neuron makes and receives with another neuroncan be different. Synapses can occur between axon terminals anddendrites, between axon terminals and cell bodies, etc.
7. Neurons can contain different types of neurotransmitters.
8. The axon of some neurons is insulated with myelin, the axon of otherneurons is not.
9. Neurons can have different numbers and different types of receptorsfor different neurochemicals.
10. Different types of neurons will be found in different concentrationsthroughout the nervous system.

Functional Differences

1. The resting membrane potential of neurons may be different fromone another (generally around -65 to -70 mV).
2. The threshold level necessary to fire an action potential may bedifferent.
3. Different neurons may have a different response to the sameneurotransmitter. For example, in one neuron, dopamine may causeexcitation (an excitatory postsynaptic potential) while in a differentneuron, dopamine may cause inhibition (a inhibitory postsynapticpotential). Remember, it is best to think of inhibition and excitation asa property of the receptor rather than a property of the neurotransmitter.
4. Different neurons may have different conduction velocities...in otherwords, an action potential will travel down the axon at different speeds.This speed is determined by the diameter of the axon and by myelin wrappedaround the axon. Some neurons have myelin, some do not. Myelin speeds upconduction velocity.

This is only the start of a list of differences between neurons. I amsure you could think of many more differences.

Ilana: Myfriend was on a rope swing and she hit her head against a tree and on theway to the hospital her mom didn't want her to fall asleep. Why cant youlet someone who has had a concussion fall asleep?

Answer (By Dr. Doug J. and Dr. Chris B. members of theNeuroscientist Network): The development of bleeding and swellingcaused by the bleeding, either above or below the coverings of the brain(the meninges) are among the more serious complications that can arisefollowing head injury. The swelling caused by blood is called a hematoma. The hematoma may result from the rupture or laceration of blood vesselsabove or below the meninges. Hematomas may increase intracranial pressurewhich is not well tolerated by the brain. If not relieved as soon aspossible (typically by surgical drainage), serious problems may result dueto the death of brain tissue.

Loss of consciousness is one of the clinical signs observed in response tothe formation of these hematomas. The loss of consciousness occursquickly as the size of the hematoma increases. If the person whoexperienced the trauma is awake, it is important to keep him or her awaketo observe any changes in mental status. For example, do they stay alert and oriented to their surroundings, or do they lapse in and out ofconsciousness. Changes in mental status are very important in diagnosingthis potentially life-threatening complication. If the person wassleeping after the traumatic event and a hematoma started to develop, itwould not be possible to detect the changes in mental status which wouldoccur as the hematoma increased in size.

Another reason for keeping the person awake after head trauma is that ifthey fall asleep the frequency and depth of breathing may decrease. Asthe frequency and depth of breathing decrease, the blood vessels supplyingthe brain and surrounding tissues dilate as part of a reflex and thepressure inside the skull increases. While this is not a problem in thenormal situation, this increase in intracranial pressure superimposed onthe increased pressure caused by the hematoma may produce even more damageto the brain. Hyperventilation of the patient is one method used to limitthe increase in intracranial pressure and the amount of damage caused bythese hematomas before they are surgically drained.

When people have mild concussions that do not require hospital admissionthe usual instruction to their family is to wake them at night every fewhours to make sure that they can still be aroused and thereby confirmthat they are not deteriorating. There is something known as a "lucidWindow" in which people initially look fine after a closed head injurybut slow intracranial bleeding results in a gradual increase inintracranial pressure, decreased brain blood flow, severe neuronal injuryand potentially death. Waking the person intermittantly is an attempt tocatch this process before it progresses to the point of permanentinjury and/or death.

Lisa.: I'mdoing a project for a class that I have and I was wonderingif it would be possible for you to share with me the average andstarting salary of a psychobiologist or of a related field. Thanks!

Answer: Unfortunately, the starting salary for apsychobiologist is going tovary quite a bit depending on the type of position being considered.Immediately after receiving a Ph.D., many psychobiologists and people inrelated neuroscience disciplines, go on to complete post-doctoralfellowships. These types of jobs often do not pay very well. Salary canrange from the low $20,000s to the mid $30,000s.

Some Ph.D.s may find faculty positions. These types of jobs may beteaching positions or research positions or a combination of teaching andresearch. Faculty positions usually start anywhere from the upper$20,000 to upper $30,000. However, depending on the "deal" that a personcan negotiate, it is possible to start at a salary a bit higher. If thejob involves research, it is not uncommon for the Ph.D. to negotiatestart-up funds to help set up the laboratory. These start-up funds canrange from $10,000 up to $100,000.

Another place a new neuroscientist may find employment is in privateindustry. I have heard that starting salaries are higher than universityfaculty positions, but I would not like to take a guess as to how muchhigher.

One reason that starting salaries vary so much is that differentuniversities in different states have different salary scales. Also, thecost of living in different states may influence the amount of money adepartment may offer a new scientist.

Here are some recent job advertisements that may help you with yourproject:

1. Neuropsychologist inMassachusetts - (scroll down the page; there are two positions withsalaries listed)
2. Reh. Neuropsychologist inCalifornia (scroll down; 2 jobs listed; salary listed)
3. NewSociety for Neuroscience Listings - there are several positions withsalary listed.
4. Nov-Dec.SFN listings - more jobs with some salaries listed.

I am sorry I cannot give you just one starting salary because there areso many variables that go into determining salary.

Liza A.: I'mtrying to figure out what I want to major in, and I'm pretty certain thatI want to study the brain. I understand that UCLA has a neurosciencemajor, but I've heard that it's better to receive a good generalfoundation in biology first and THEN perhaps delve into the study of thebrain further in graduate school. What is your opinion on this issue?

Answer: There are several different routes thatyou can take on your way to become a neuroscientist. Neuroscientists comefrom many different backgrounds. I have some colleagues who did not gointo neuroscience until after they received their Ph.D. in otherdisciplines. Others get their Ph.D. in neuroscience (or a related discipline) after receiving an M.D. degree.

You are right when you say a firm background in biology is important.However, I think this is important not only for the basic informationthat you receive, but also to make sure that it is the biological sciencesthat interest you.

Personally, I did not decide to go into brain research until I was asenior in college. I did not take my first biology or psychology classuntil I was a junior at UCLA. You see, up until this point, I wanted to bea marine biologist! The most important turning point in my studies was myexperiences working in a laboratory studying the brain mechanisms of painand analgesia. This experience was in the laboratory of Dr. JohnLiebeskind (who passed away this last Fall).

While in Dr. Liebeskind's laboratory, I learned what it is like to collectdata, perform experiments, and write up papers. I was able to co-author afew papers and abstracts and even wrote a small grant application. ISTRONGLY encourage you to volunteer (or get a work study position)in a laboratory to see if research is really what you want to do.

UCLA has a huge community of neuroscientists spread out over severaldepartments. For more information and possibly for leads into alaboratory, try:

• UCLANeuroscience Undergraduate Society
• The NeuroscienceMajor at UCLA
• InterdepartmentalNeuroscience (Ph.D.) at UCLA
• UCLA Neurobiology
• Brain ResearchInstitute (UCLA)
• UCLA PsychologyDepartment

Toni G.: Iread the Stroop effect page with the unlabelled illustration of the brain.Neither the text nor illustration indicated what the anterior cingulatewas. Was it the red dot? Or the green area on the brainstem? I don'thappen to have an anatomy or psychology text handy, or I'd look it up.

Answer: I see your problem. You followed the linkon my Stroopeffect page to the "Jay's Brain" page onthe the Stroop effect. The picture of the brain you are having troublewith is on his page, but I can explain it to you. By the way, yourquestions are quite good...the text and/or picture SHOULD have beenlabelled by the authors of this page - you are quite right.

The RED spot on the picture points to the anterior cingulate gyrus (alsocalled anterior cingulate cortex). The GREEN spot located near thebrainstem is actually in the 4th ventricle for some reason....I have noidea why!! I have a similar picture on my site that labels the cingulategyrus (the anterior cingulate gyrus is just the "anterior" or front partof the gyrus). This picture can be found at: http://faculty.washington.edu/chudler/sagittal.html

B. Aus.: I amvery interested in your suggestions for an 8th grade science fair project. Any ideas or suggestions would be greatly appreciated. I am especially interested in brain topics.

Answer: I think a science fair project related tothe nervous system would be a great idea. Last year I visited a sciencefair and I did NOT see any projects related to the brain.

I would suggest that you start by looking over the experiments andactivities on my page:http://faculty.washington.edu/chudler/experi.html

Many of these experiments are demonstrations rather than science fairprojects, but with a little thinking on your part, you could turnone of these ideas into a project. Look over the experiments on this pageand you should find something that interests you.

Severalpeople: I have heard that we use only 10% of our brain. Is thistrue?

Answer: I am asked this question many times. Somany times in fact, that I have created a separate page called:

Shannon R.: Iam doing an essay on how the memory of a human changes as they growolder, but am not quite sure were to start. Is there any informationthat proves that your memory improves or gets worse as you grow older?I was also wondering which part of the brain controls your memory. Arethere any other websites that may help me?

Answer: As with many questions about the brain,there are no simple answers. As people get older, there are definitechanges in behavior including changes in sleep habits, movement patternsand mental function. There is a great amount of variation between peopleof the effects of age on mental function. It is apparent that manyintellectual functions (including memory) do change in people, but thatthis change does not necessarily decrease their quality of life.

Data show that changes in the brain later in life may include:

1. Reduced brain weight
2. Reduced level of protein in the brain
3. Reduced number of neurons in the brain (especially in cerebral cortex)
4. Reduced levels of enzymes that produce the neurotransmitters dopamineand norephinephrine.
5. Reduced number of receptors for dopamine, norepinephrine andacetylcholine.

However, as I said, there is a wide range in changes that occur. NOT allolder people have memory problems. On the other hand, as people getolder, there is more and more "chance" of neurological disorders thatinclude memory problems. For example, Alzheimer's disease is rarely seenin young people.

With regard to your question about where memory is located, this is also adifficult question. There seem to be several areas of the brain that playa role in memory including the cerebral cortex and hippocampus and othersubcortical areas. To read more about memory, here are some good articlesthat you can find on the Internet:

1. http://www.apa.org/monitor/oct96/squire.html
2. http://www.latimes.com/thebrain/
3. http://www.epub.org.br/cm/n01/memo/memory.htm
4. http://www.apnet.com/inscight/07081997/graphb.htm
5. http://www.ama-assn.org/sci-pubs/journals/archive/neur/vol_54/no_10/ed7245x.htm

Also, if you want to find out some more about Alzheimer's disease, go tomy NeurologicalDisorders page.

What is thehardest tissue in the human body? What are 3 suggestions for good brainhealth?

Answer: Sounds like a homework question. Theanswers to your questions are on two of my web pages.

Go to: TheTooth and BrainFitness

Darren W.: Could you compare and contrast the Brain and the reflex nervous system,but the only problem is that i need it for tomorrow please help me!!

Answer: Sounds like another homework question. Ithink the best way to help you is to tell you about a few places on theWWW were you can get your own answer. Try:

1. http://www.ktca.org/newtons/13/rlxes.html
2. Neuroscience forKids Page on Reflexes
3. http://cuba.k12.nm.us/sci/reflex.htm

I was wonderingif you could tell me when do our brains stop developing and connectingneurologically? Are we still able to improve brain power later inlife? When does the window of opportunity for math close and can wecontinue to develop math/logical thinking?

Answer (By Dr. Jim C., member of the NeuroscientistNetwork): This is a somewhat difficult question to answer simply,because we need to do much more research to answer these questions moreprecisely. Different parts of our brains develop at different rates, somestarting early before we are born and other regions starting after we areborn. Also, different aspects of the development of our brain end atdifferent times. If we look at the development of connections betweennerve cells (called synapses), then one of the latest regions of ourbrains to stop forming synapses is the prefrontal cortex, the outer regionof the brain directly behing your forehead. Here the process of synapseformation goes on into mid-teen years. But it may surprise you that moresynapses does not always mean a better functioning brain. In many brainregions, an overabundance of synapses are usually formed during the firstfew years of life before a "pruning or cutting back" of synapses occurs toreach a relatively stable number.

If we look at the development of the insulation that helps nerve fibersconduct information faster between nerve cells (called myelin), then thereare other regions of the brain that are thought not to be completelymyelinated until the mid-20's!.

There is no doubt that we can continue to improve our brain power later inlife. Part of the basis for learning and memory processes in the brainare considered to be represented by changes in the structure as well asfunction of the nerve cells involved in the activity. These structuralchanges are due to the forming and reforming of connections between nervecells as indicated by changes in the structure of individual nerve cells: their sending parts (axons) and their receiving parts (dendrites). Nearlyall mental abilities, including math and logical reasoning can bemaintained, perhaps not as quickly for someone in their 70's or 80's, butjust as researchers are finding that physical activities help the bodystay healthy, mental activities also have great benefit for keeping thebrain healthy.

In the not-so-distant future, I suspect that newer techniques of brainimaging that are being used will help us to better understand thestructural and biochemical changes that underly the formation of memoriesand learning as we develop our mental capacities through school years andadulthood.

FromFernando P.: I'm a Psychology teacher in the last level of asecondary school. The next year students will be studying Medicine, Biology orPsychology. Or they'll stop studying. Next month I'll begin thesubject about the Nervous System. What do you think it's really importantto teach them about this subject, more important than all the fastidiousclassifications and scientific names? How to speak them about the dynamics of the Nervous System and the Brain? Can you give me any sugestions? Thankyou and congratulations for your work. I deeply appreciate it.

Answer: I think that every instructor will have adifferent answer to your question. However, I will give you my ownsuggestions about how to approach these students.

It is my belief that an introductory class in neuroscience (orpsychobiology or physiological psychology) should be approached by ateacher in much the same way that a fisherman prepares to go fishing. Thefisherman is the teacher and the fish are the students.

A fisherman must have the correct tools: a fishing rod, hooks,line and bait. A teacher must have the correct tools: the basic knowledgeof the subject matter and the methods to relay this knowledge to thestudents. I consider the "bait" that the teacher uses to be critical...theteacher must use the correct bait to maintain the interest of the student. The goal of the fisherman and the teacher of an introductory class issimilar. The fisherman wants to hook the fish and reel it in. The teacherof the introductory neuroscience class should want to "hook the students"- to make the students want more; to make the students want to takeanother class that explores the subject matter in more detail. Whenever alesson can be applied to the students' everyday experience or can bereinforced with "hands-on" demonstrations or activities, the bait is madeeven more attractive.

In the introductory class, it is impossible to cover the allaspects of the nervous system. I share your view that there are manynames, pathways and other vocabulary that can get students distracted.However, I believe that learning of some new vocabulary is essentialbefore you can engage students in meaningful discussion of the nervoussystem. The basic planes of sections and directions should be discussedimmediately. This subject can be a bit dry and boring, but it can be mademore interesting by demonstrations.

I would then go on to the very basics of the nervous system: theneuron, the action potential and the synapse. Again, using manydemonstrations and activities to illustrate concepts. It is also necessaryfor you to lay out the framework of the nervous system by introducing thenames of various structures of the nervous system.

Following the synapse, you might want to discuss neurochemistry,drug effects and altered states of consciousness. This may be especiallyrelevant to many of your students who may be thinking of experimentingwith drugs.

The senses can be a favorite area of study for many students. Students can use themselves as test subjects to investigate touch, taste,smell, hearing and vision. The senses offer you many possibilities forin-class experiments. My favorite is the blind spot test - when an imagedisappears into students' blind spots, the expression on their faces ispriceless.

Other favorites of many students are the higher cognitivefunctions: language, thought, memory. Still other students find sleep andemotion fascinating - and they are! Many students may have relatives whohave neurological diseases - this is a good chance to relate what is knownabout such disorders with a student's personal experience. It depends onhow much time you have to teach. It is probably not possible to coverevery topic. However, for each different topic, use as many demonstrationsand experiments that you can.

My suggestion to you is to be like a fisherman. Use the best baitthat you have - with skill, practice and a little luck you will hook manyfish.

From DaveM.: Many studentsare making college selection choices now and few know what theprofessional life of a scientist is like. One question you may help mystudents with - Can you suggest ways that students might identify collegesor universities that will prepare them well for a profession inneuroscience, or science in general?

Should students be involved in research? while in high school? as anundergraduate in college?

What are the benefits / problems with doing this?

How might one arrange to do research in a lab similar to yours?

Certainly if the opportunity to become involved in research while inhigh school is there, I would encourage students to participate. Asundergraduates at the university, students will find many moreopportunities to get into the laboratory. Often there are advertisementsposted around the university for lab assistants and many departments keeplists of lab jobs.

The skills necessary to perform neuroscience research are varied. Someskills are very technical requiring advanced training. However, manyopportunities for undergraduates exist in laboratories performingbehavioral experiments. As an undergraduate (junior and senior years) atUCLA, I worked in the laboratory of Dr. John Liesbeskind and was able toco-author 2 papers published in scientific journals. It wasn't until thistime that I decided to pursue a career in Neuroscience.

From JohnM.: I'm interested inthe "holographic" theory of memory and how the brain/neurons store, recalland can be re-trained to respond in new ways with practice. How doesdesire, purpose, emotions, and interactions with people (the instructor)make learning more or less successful? What gets people "ready" tolearn?

1. When an animal is stressed or aroused, chemicals (hormones) inthe body are released. If these "stress" hormones are given to an animalimmediately after training, then the animal will remember the trainingbetter than if the hormones were not given.

2. Injection of drugs that affect a variety of neurochemicalsystems can influence memory.

3. Both Drs. LeDoux and McGaugh have hypothesized that abrain structure called the amygdala has a role in the effects that emotion has on memory: injection of drugs into the amygdala or destructionof the amygdala can influence "emotional memory".

4. Dr. McGaugh has performed fascinating experiments with human subjectscomparing the memories of subjects shown emotional scenes with thememories of subjects shown unemotional scenes. These experiments werehighlighted in a recent PBS special called Piecesof Mind and I would highly recommend visiting this site for moreinformation.

1. Would an "emotionally-charged" training session result inenhanced learning and memory of the material you present?
2. Would a stressful training session help (or hurt) learning and memory?
3. What is the role of attention in memory and learning and how can youmake use of this in training?

Perhaps we will soon be able to answer some of these questions by applying basic science research to real life situations.

From CarolynP.: Dr. Chudler,can you describe the type of research you are conducting in yourlaboratory?

Answer: I currently have 3 research interests:

1. The mechanisms by which the basal ganglia (the caudate nucleus,putamen, globus pallidus) process somatosensory, auditory and visualinformation. An understanding of how the basal ganglia process sensoryinformation may shed light on how the nervous system responds toenvironmental cues and how organisms make use of these cues to makeappropriate behavioral responses. Moreover, this line of research maylead to data concerning the etiology of Parkinson's Disease, and provideinformation leading to potential treatments for this debilitatingdisorder. (for more information on conditions such as Parkinson's disease,see Neurological Disorders.

2. The role of the cerebral cortex in pain and nociception. The role ofthe cerebral in pain is poorly understood. The neurobiology of pain isvery difficult to study since it is a very complex behavior. Pain is"multidimensional":
   • Pain has a sensory component - where is the pain, how much pain,etc.
   • Pain has a motivational/affective component - it stirs emotions andincreases drive to reduce pain.
   • Pain has a cognitive component - you learn from pain and it draws your attention. The goal of this research is to devise treatment for people with chronic and acute pain. For more on pain, see the InternationalAssociation for the Study of Pain home page.

3. My last research interest is in the response of the nervous systemto peripheral nerve injury. I hope that this line of research will lead totherapies and treatments for patients who have sustained damage to variousnerves.

From CarolM.: A report earlierthis year (1997) suggests that ibuprophen, a common anti-inflammatorydrug, reduces one's risk of developing Alzheimer's disease. Any commentson this study?

Answer: The recent paper concerning the role ofanti-inflammatory drugs to reduce the risk of Alzheimer's Disease (AD)suggests a new treatment strategy to control this devastating degeneratingbrain disorder. At this time, the cause and cure for AD are unknown.

For those of you with access to a medical school library, this paper can be found in the journal called Neurology, volume 48, pages 626-632,1997.

This study was based on the hypothesis that inflammatory processes in thebrain have a role in the generation of AD. This is NOT a new hypothesis -rather, there are several prior papers that advance this theory...forexample:

1. Aisen-P-S., Inflammation and Alzheimer disease. Mol-Chem-Neuropathol.1996 May-Aug. 28(1-3). P 83-8.
2. Thal-L-J.,Potential prevention strategies for Alzheimer disease. Alzheimer-Dis-Assoc-Disord. 1996 Fall. 10 Suppl 1. P 6-8.
3. McGeer-P-L. McGeer-E-G.The inflammatory response system of brain: implications for therapy of Alzheimer and other neurodegenerative diseases. Brain-Res-Brain-Res-Rev. 1995 Sep. 21(2). P 195-218.
4. McGeer-P-L. McGeer-E-G. Anti-inflammatory drugs in the fight againstAlzheimer's disease. Ann-N-Y-Acad-Sci. 1996 Jan 17. 777. P 213-20.
5. Wong-P-T. McGeer-P-L. McGeer-E-G. Decreased prostaglandin synthesis inpostmortem cerebral cortex from patients with Alzheimer's disease.Neurochem-Int. 1992 Sep. 21(2). P 197-202.

However, this new study is the first to look at such a large populationof subjects and to examine them over a long period of time. Briefly, theseresearchers found that in a long-term study that people who take non-steroidal anti-inflammatory drugs like ibuprofen appear to have a lessrisk for developing AD.

This is an exciting finding because it provides data to confirm the hypothesis regarding a role of inflammation in the generation of AD andsuggests that drugs to target the inflammatory process may reduce thesymptoms of AD and prevent the development of AD.

These results are still preliminary and caution must be used in the interpretation of the results. The link between inflammation and AD stillneeds further research. Moreover, these researchers found that aspirin,also an anti-inflammatory drug, did not reduce the risk of AD. Also, theexperiment design of these study was one of correlation. The mostimportant thing that I remember from my statistics classes was that"correlation does not mean causation". In other words, just because onething correlates with another does not mean that one thing CAUSES theother. I hope that clinical and experimental testing will resolve thisissue.

The possible side effects of anti-inflammatory drugs must also be considered. These include altered kidney function and peptic ulcers. Moreover, there may be unwanted drug interactions between anti-inflammatory drugs and AD drugs that produce side effects.

Regardless of these concerns, this recent paper gives hope that new effective treatments and even a possible cure for AD are just around the corner.

For more on Alzheimer's Disease, see the Neurological Disorders Page.

From BillH.: I am a sophomorein High School I am interested in becoming a biologist and have a fewquestions. I am particularly interested in genetics. What would be some ofthe best colleges for me to attend. Do you know if the University ofNebraska has a good program in biology?

I will complete science courses in biology, chemistry and physicsbefore I graduate. I will also complete math courses in geometry, algebraand introductory calculus. Are there any other courses that I should tryto take to prepare myself to major in biology in college.

There are so many decisions that go into selecting a college that I will not make a specific recommendation. This is a decision that is bestdecided by you with help from your parents and perhaps your teachers.However, let me point out that for further information about theUniversity of Nebraska Department of Biology, see:

1. Biological Sciences at theUniversity of Nebraska-Lincoln
2. University of Nebraska atOmaha Dept. of Biology
3. Nebraska Behavioral Biology GroupHome Page

From RenitaC.: A few years ago,I ran across an article in Harper's about an anatomist that had done someholographic work on the brains of salamanders. I was wondering if you'dheard of this man's work? It has to be almost twenty years old. I'veforgotten his name, I believe it was Paul something. He is or was locatedin Bloomington Indiana, affiliated with the university there. I spoke withhis wife, Jane. (yes, I actually tracked down a celebrity), she'd told meshe'd assisted her husband with his work at that time. I didn't get tospeak with the doctor himself and was wondering if there were follow upstudies with his work. It dealt with memory and the restoration offunction to parts of the brain that had been destroyed due to injury. Have you heard anything?

From RenitaC.: My questionshave to do with nerve agents. I work with quite a few chemicals andrecently came in contact with something that might have had a temporaryeffect on my parasympathetic nervous system. I was wondering if you couldpoint me to some other resources that could help with antidotal treatmentbased on symptom alone, when one is unaware of the chemical with which onehas come in contact. Like if something is slowing the heartbeat it couldbe hormonally stimulated, or it could be a toxin. Well this "blixit" couldbe the universal antidote in that situation. Is there any reference asidefrom the good old pharmacology textbooks and warning labels MSDS etc.

Answer: Of course the first thing to do if you arehaving health problems is to see a physician. The physician may beable to refer you to a toxicologist or environmental health specialist whocan be of more assistance.

As far as finding out more about toxins, neurotoxins, and the autonomicnervous system there are several good sources:

1. Neurotoxins- this is a page that I have developed for the Neuroscience for Kids -this page describes many neurotoxins. I also have created a briefdiscussion of the autonomic nervoussystem.
2. Environment Writer-- Chemical Backgrounders - this is a list of the effects of manychemicals that you might find in the workplace.
3. ToxFAQs:Hazardous Substance Fact Sheets
4. AutonomicPharmacology - from the Univ. of Washington

From KimE.: You know the oldacronym for remembering the cranial nerves, about "on old Olympus toweringtops a Finn and German viewed some hops." Well, I was wondering if you hadanother acronym?

Answer: You have listed the mostwell known mnemonic device for the 12 cranial nerves. This type ofmnemonic is called an acrostic. I have updated this mnemonic because theeighth cranial nerve is now better known as the vestibulocochlear nerverather than the auditory nerve. Instead I purpose the follow mnemonic: "On old Olympus towering top a famous vocal German viewed some hops".There is one other well known mnemonic for these nerves, however, it issomewhat "X-rated"...the first 5 words are Oh, Oh, Oh, to, touch,...Iwill not repeat the complete mnemonic here...you will have to ask someoneelse.

Another mnemonic for the cranial nerves concerns whether they are only sensory, only motor or both sensory and motor. The acrostic for this is:"Some Say Marry Money, But My Brother Says Big Business Matters More". Thefirst letter of each word signifies whether the particular cranial nerveis sensory only (S); motor (M); or both sensory and motor (B). So, the "S"in the word "Some" means that the first cranial nerve (the olfactorynerve) is sensory only; the "S" in the word "Say" means that the secondcranial nerve (the optic nerve) is sensory only...etc.

One more mnemonic for the first two cranial nerves only is "You have onenose and two eyes"...therefore, cranial nerve I is the olfactory andcranial nerve II is the optic. Of course, this only helps for the firsttwo nerves.

See "Neuroscience for Kids" on the cranialnerves for more information.

From BarbaraW.: I teach fourthgrade and plan to do a unit in the Fall on the brain. Would it be okay ifmy students wrote questions to you here? Also, I teach college educationcourses, one on constructivism. I would appreciate receiving someinformation on what happens in the brain when we pull together previousexperiences and new information to create new concepts. Thanks for yourhelp.

Answer: Glad to hear that you will be doing a uniton the brain with your fourth grade class. I would prefer that yourstudents address questions directly to me at my email address: chudler@u.washington.edu

Your question about using experiences (memories?) and new informationto create new ideas is intriguing. Unfortunately, scientists are onlybeginning to understand some of the basic mechanisms involved withlearning and memory. I hope that I will have a better answer for you whenmore is known about the neural mechanisms of memory and learning.

From SachinA.: I'm currentlygetting a B.S. in neuroscience and philosophy at Texas Christian U. Idefinitely know that I want to have a career in academic medicineinvolving neuroscience research with non-human primates, plus teachingneuroscience to med/grad students. This means getting both an MD(withoutresidency) and a Ph.D. Can you tell me about the MSTP program at Univ. ofWash, and of any current neuroscience research involving non-humanprimates at U of Wash that you may know of?

Rather than describe the entire M.D. program available at the UW, I'll letyou decide what you want to find out...here are several sources thatshould answer your questions about the medical school:

1. University ofWashington Medical Center
2. University ofWashington School of Medicine

There are several departments on campus that use non-human primates neuroscience research. The UW is home of one of the Regional Primate Research Centers. (Sorry, no home page for them that I know.) Many of theinvestigators who belong the Regional Primate Research Center also haveaffiliations with other departments such as:

1. Department of BiologicalStructure
2. Neurobiology andBehavior
3. Department ofPsychology

I would suggest you browse these department pages to see the currentresearch of the faculty.

Good luck with your studies.

From Gurumurthy.S.: I amcurrently doing my postgraduation in Computer Science and Eng. at IndianInstitute of Tech. I did my Bachelor of Engineering in Computer Science. Iam very much interested in Neural Networks and in modeling the brain usingcomputers. I have not got much exposure to Neuroscience, which I thinkwould help me very much. I intend to do a Ph.D. in Neuroscience. Couldyou please tell me where I could do it and what must I do for it?

From RachaelF.: I will beteaching a neuroscience course to 12^th grade students thisspring. I want them to follow NeuroLab going into space in March 1998. Icontacted what I thought was the good link at NASA but don't think this isgoing to help. Are there any experiments that would be possible for us toconduct while Neurolab is in space?

Answer: There are a few Web sites for the 1998 Space Shuttle"NeuroLab":

1. NeurOn
2. NeurOLab
3. International Neurolab Program
4. Neurolab Human Life Sciences
5. NeuroLab - I
6. STS-90
7. Mission - NeuroLab
8. NeuroLabActivities

From JosephF.: I am currentlystudying Neurosci at the undegrad level. I am perplexed at what I am goingto do with my education. I assume I will obtain an M.D./Ph.D. in Neurosci.I am interested in the development of virtual tech. I want to also havethe capability of a neurosurgeon, for its obvious role in the interfacingof VR with people. What will I call myself? What will I be? How do I studysomething we haven't developed? How do I develop it and what do I study todo so.

Answer: Some of the most innovative work in thelife sciences is being done by utilizing new technologies in medicine.There are even some groups that are pursuing the use of virtual realitywithin the realm of neurosurgery. For example see:

1. VirtualReality of Neurosurgery
2. 3-DimensionalNeurosurgery

An M.D./Ph.D. program is probably the best way to go to get into this field. It would also be best to ask people at the medical schools you areinterested in about the type of training you will receive. You may alsowant to consider bioengineering departments that have projects that focuson this type of work. You may be able to participate in an ongoing projectwhile you are still in school.

From AmandaW.: I'm interestedin pursuing a career in Neuroscience. What Universities do you feel offera superior degree program in the field? I also wondered if you knew of anyresearch programs in Houston that might be in need of be willing to takeon an inexperienced undergraduate student?

Answer: According to a recent US News and WorldReport article, the following schools were rated to be the top fivefor graduateschools for Neuroscience:

1. Harvard University
2. Johns Hopkins University (Md.)
3. Yale University
4. Stanford University
5. University of California at San Francisco

Personally, I would add to this list: University of Washington; University of Minnesota; Massachusetts Institute of Technology; WashingtonUniversity, University of California (Los Angeles, San Diego andBerkeley Campuses).

Concerning research programs in the Houston area - I would suggest thatyou look over the programs offered at:

1. Baylor College of Medicine(Division of Neuroscience)
2. UT Houston, Dept. ofNeurobiology and Anatomy

These two WWW pages contain information about the research going on at these universities and a short description of the faculty. If you see aprogram that interests you, then contact the people involved in the lab.You never know if they will need someone to help out.

From AllanN.: Can a person bevery smart with a little brain? What is the largest human brain known?

Answer: Well, it depends on how little. Anaverage brain weighs about 3 pounds (1,300-1,400 gm) The smallest knownhuman brain in a normal person is from a 46 year old man - this brainweighed only 1 pound 8 oz. (680 grams). The largest brain known is from a30 yr. old man - this brain weighed 5 pound, 1.1 oz (2,300 gm). Thesestatistics come from the Guinness Book of World Records. However,there is no relationship between the size of a person's brain and howsmart they are. See the page on brain size formore information on this topic.

From Marc M.: In our 6th grade science class we are studying electricity. Don't natural electric impulses send the messages given off by the brainto the rest of the body?

Answer: Yes, you are right. The nervous systemworks using an "electrochemical" process. Read more about this at my pageabout action potentials at:

http://faculty.washington.edu/chudler/ap.html

and about the differences between the brain and a computer at:

http://faculty.washington.edu/chudler/bvc.html

For other neuroscience question/answer pages, see:

1. Ask Dr.Universe
2. Ask anExpert - Neurology
3. Mad Scientist's Network -Neuroscience
4. PlanetScience - Your Body
5. ScienceNet Database Search
6. Scientific AmericanAsk An Expert - Biology
7. Scientific AmericanAsk An Expert - Medicine
8. University of MinnesotaBrain Awareness Week Page