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 Ask a Question | You've got the questions; here are the
answers....well, at least some of them. Here at "Neuroscience for Kids,"
a team of neuroscientists has been assembled to answer your questions
about the nervous system. The team consists of basic and clinical
neuroscientists from around the world who will try their best to answer
your questions. Send your questions to Dr. Chudler at chudler@u.washington.edu. The
answers will be posted as soon as possible. (The more recent questions
are posted at the top of this page.) NOTE: the Neuroscientist Network will not diagnose your illness or give you medical or legal advice. Feel free to ask questions related to particular disorders and diseases, but please see a physician if you have any personal health concerns. |
Answer: Colliding action potentials cancel each
other out because the refractory period of either spike prevents the
continuation of an impulse in either direction.
Answer: It depends on what segment of the spinal cord and which plane you
measure:
Midthoracic area (tranverse diameter) = 10 mm
(Reference: Carpenter, M.B. and Sutin, J.S. Human
Neuroanatomy, Baltimore: Williams & Wilkins, 1983.)
Answer: Ballismus comes from the Greek word
"ballismos" meaning "a jumping about" or "dancing."
Answer: Gray matter consists primarily of neuron
cell bodies. For example, in the brain, gray matter forms the outside
layers of cortex and nuclei deep within the brain. White matter consists
of myelinated axons.
Answer: The knee jerk reflex helps with posture.
When the knee bends, it stretches the leg muscle (quadriceps femoris).
The muscle stretch starts the reflex and the leg straightens.
Answer: Few studies have examined gender
differences of the effects of MDMA. However, Liechti et al. (2001)
reported that the perceptual changes, anxiety and adverse effects (e.g.,
jaw clenching, dry mouth, appetite changes) of MDMA are greater in women
than in men. Blood pressure increases caused by MDMA are higher in men
than in women.
Reference: Liechti, M.E., Gamma, A. and Vollenweider, F.X. Gender
differences in the subjective effects of MDMA. Psychopharmacology
(Berl). 154:161-168, 2001.
Answer: It depends on the drug and the test.
Urine tests are the most common way drugs are detected. However, samples
of a person's blood, saliva, breath, sweat and hair can also be tested to
detect drug use. The presence of breakdown products (metabolites) in a
sample are an indication of drug use.
According to The Medical Letter, August 19, 2002 (Volume 44),
the following drugs can be detected in urine:
Answer: You can find a good list at the National
Institute of Neurological Disorders and Stroke. There is a link at
the top of that page "Request mailed brochures" where you can have free
publications about various neurological disorders mailed to you.
Another good resource is Brain
Connections, a PDF booklet with email addresses, phone numbers and web
sites of various support organizations.
Answer: According to the Centers for Disease Control
and Prevention:
"Tobacco use remains the leading preventable cause of death in the United
States, causing more than 440,000 deaths each year and resulting in an
annual cost of more than $75 billion in direct medical costs."
Answer: Yes, there are case reports of visual
disturbances after methamphetamine use. See:
Answer from Dr. Pat F. (Neuroscientist Network
member): The motor coordination between upper and lower limbs is
interconnected, both unilaterally and bilaterally. These interconnections
are a holdover from our quadrupedal gait patterns. They are an
evolutionary holdover, but are functional early in life. Recall that all
humans, despite being considered bipedal (walking upright on our lower
limbs), we are quadrupedal in our early stages of life (crawling as a
child). These interconnections serve to provide a coordinated sequencing
of movements of the upper and lower limbs. Evidence of these circuits and
their retained functionality even in the adult is noted with the arm swing
during walking. While some of the movement is passive, there is indeed
increased muscle activity and even spinal motor neuron activity
corresponding to these movements. This is evidence that they are not
simply passive, but actually driven by nervous system activity. If you
analyze the arm swing during bipedal gait, you will notice that it
corresponds to the same sequence observed with a quadruped gait. These
circuits are relatively easily overpowered by conscious voluntary control
from higher centers. So... Short answer, the control of upper and
lower limb movements is influenced by 'old' reflex circuitry within the
spinal cord and this circuit tries to maintain a symmetry of movement.
Answer: A tract is a
collection of nerve fibers (axons) in the central nervous system. A nerve is a collection of nerve fibers (axons) in the
peripheral nervous system.
Answer: Someone sent me the cookie cutter that I
have, but I do not know where they bought it. I found some available on
the Internet at:
http://www.kitchengifts.com/working.html
Answer: Yes, most fish have tongues. For more
information about this topic, see the answer to this question provided by
the Australian Museum Fish
Site.
Answer: According to The Handy Science Answer
Book (1994) compiled by the Science and Technology Department of the
Carnegie Library of Philadelphia, the human body is composed of:
Potassium, sulfur, sodium, chlorine and magnesium each occur at 0.35% or
less. There are other elements found in trace amounts.
Answer: A beta-blocker is a drug that binds to
beta receptors thus stopping the action of the neurotransmitter called
norepinephrine. These drugs work by blocking the action of the sympathetic nervous system on the heart. They can
prevent increased heart rate and pumping strength and are used to treat
high blood pressure and irregular heartbeats.
Answer: Many new Ph.D. scientists take
post-doctoral fellowships funded through a National Institutes of Health
(NIH) grant. The current
stipends set by NIH for these fellowships depend on how much
experience you have:
Answer: Yes, MDMA and
Ecstasy are the same thing. MDMA is the abbreviation for the chemical
name of Ecstasy: 3,4 methylenedioxymethamphetamine.
Answer: Doves, White Doves and Love Doves are
other names for the drug Ecstasy.
Answer: As people age, their ears get larger. Ear
circumference increases an
average of 0.51 millimeters per year. (Source: "Ear size as a predictor of
chronological age," by R. Tan, V. Osman, and G. Tan. Archives of
Gerontology and Geriatrics, Vol. 25., page 187, 1997.)
Answer: J. Ridley Stroop published his paper about
the famous colored word task in 1935. You can
read his original
paper on the Internet.
Answer: For a period of time, Einstein's brain WAS
in the basement of a house in New Jersey. Here's the entire story.
Albert Einstein died at 1:15 am on April 18, 1955 at Princeton Hospital in
New Jersey. Later that day, Princeton Hospital pathologist Dr. Thomas
Harvey performed an autopsy on Einstein and removed Einstein's brain.
Harvey cut the brain into 240 pieces. He was very protective of the brain
and kept it in jars at his house. Over the years, Harvey gave several
pieces of the brain to different researchers including Dr. Marian Diamond
(UC Berkeley), Dr. Britt Anderson (University of Alabama) and Dr. Sandra
Witelson (McMaster University, Hamilton, Ontario). Harvey moved around
the country and he always brought the brain with him. Eventually, Harvey
moved back to New Jersey. In 1996, Harvey brought the remaining pieces of
Einstein's brain to Dr. Elliot Krauss, chief pathologist at Princeton
Hospital.
(Reference: Abraham, C., Possessing Genius: The Bizarre Odyssey of
Einstein's Brain, New York: St. Martin's Press, 2002.)
Also, see: What Became of Albert Einstein's
Brain?
Answer: Yes, people with split brains (cut corpus callosum) DO dream. A report of
dreaming in such people was publised in 1977 by Greenwood, P., Wilson,
D.H., and Gazzaniga, M.S. (Cortex, 13:311-316, 1977) called
"Dream report following commissurotomy".
Answer: According to Principles of Neural
Science by Kandel, Schwartz and Jessell (2000; page 20):
"Astrocytes, the most numerous of glial cells, owe their name to their
irregular, roughly star-shaped cell bodies..."
Answer: Curare is a poison that comes from various
plants in South America. Curare
causes paralysis and works at the neuromuscular junction by blocking
nicotinic receptors for the neurotransmitter
acetylcholine.
Answer: Yes! There is a great site with many
pictures (click on the "images" button) at:
http://www2.healthcare.ucla.edu/conjoined_twins/index.asp
Answer: When it is light outside for 24 hrs each
day and in temperatures of approximately 0.8oC, Emperor
penguins spend 45.1% of the entire 24 hour day asleep. In alternating
day/night conditions and in temperatures between -14oC and
-17oC, these penguins spend 41.3% of the entire 24 hour day
asleep.
Answer: Yes, the active ingredient of marijuana
can show up in a person's system after being exposed to "second hand"
marijuana smoke. However, the person must be exposed to a heavy
concentration of smoke for this to happen. Here are some
summaries of studies on this topic:
Answer: No. There are no muscles in the brain.
There are muscles in the head and face, but none in the brain itself.
Answer: The inability to smell is called
"anosmia." The complete inability to taste is called "ageusia" and the
reduced ability to taste is called "hypogeusia." Ageusia is a rare
disorder.
Answer: Otto Loewi, who won the Nobel Prize for
his work on chemical transmission of nerve
impulses, was born in Germany. However, he worked in Austria and the
United States. He also became an American citizen in 1941.
Answer: A bottle-nose dolphin brain weighs
between 1,500 and 1,600 grams. An average adult human brain weighs about
1,400 grams. See the Mammalian
Brain Collection for some photographs of the dolphin brain.
Answer: The primary function of the bee tongue is
for ingestion of liquids and
exchange of food and pheromones between bees. However, electron
microscope photographs of the bee tongue show "buds" suggestive of taste
receptors (Erickson et al., 1986). Also, Seeley (1995) states that
chemoreceptors on the mouthparts of bees provide a sense of taste. Bees
also have taste receptors located on their feet and legs.
References:
Answer: I have seen figures for the energy
consumption of the brain ranging from 10 to 25 Watts. The human body
consumes about 100 Watts (Body, Physics of, in Macmillan Encyclopedia
of Physics, New York: Macmillan, 1996). The brain uses about 20% of
these resources. Therefore, the brain consumes about 20 Watts of
energy.
Answer: The outer ear and most of the nose are
made of cartilage, not bone. Cartilage decomposes
and is usually not preserved.
Answer:
Not only cockroach, but many different types of insects and not just in
chocolate!
The US Food and Drug Administration (FDA) has set limits "...to establish
maximum levels of natural or unavoidable defects in foods for human use
that present no health hazard." Such unavoidable defects include insect
fragments in our food.
According to the FDA web site: The
maximum level of defects in chocolate is an average of "60 or more insect
fragments per 100 grams when six 100-gram subsamples are examined OR any
one subsample contains 90 or more insect fragments."
If you don't mind getting "grossed out," you can also go to the FDA web
site to find out how many insect eggs, rodent filth, and mold are allowed
in other foods. However, I urge you to be prepared for what you will find
out!!
Answer: The cat has 38 pairs of spinal nerves (8
cervical; 13 thoracic; 7 lumbar; 3 sacral and 7 caudal nerves - Reference: Gilbert, S.G., Pictoral Anatomy of the Cat,
Seattle: University of Washington Press, 1975). Humans have only
31 pairs of spinal nerves (8 cervical; 12 thoracic; 5 lumbar; 5 sacral and
1 coccygeal nerve). Answer: The cell bodies of the parasympathetic nervous
system are located in the spinal cord (sacral region) and in the medulla.
In the medulla, the cranial nerves III (oculomotor nerve), VII (facial
nerve), IX (glossopharyngeal nerve) and X (vagus nerve) form the
preganglionic parasympathetic fibers.
Answer: It is rare, but some
people do smell things during dreams.
Answer: The independent variable is the thing that
the experimenter will change in an experiment. The dependent variable is
the thing you will measure because you expect it to change. For example,
in an experiment to determine if the color of food affects the sweetness
of food: the independent variable is the color of food because the
experimenter will be changing the color of food; the dependent variable
might be a rating of how sweet the food tastes to a test subject. Answer: Tetrodotoxin (a neurotoxin) is concentrated in the liver, gonads,
intestines and skin of the pufferfish.
Answer: Yes. Both giraffes and humans have SEVEN
cervical vertebrae.
Answer: The island of Reil is another name for the
insula, a large part of the cerebral cortex that is buried in the lateral
sulcus of the brain. The word "insula" is Latin for "island." Johann
Christian Reil (1759-1813) is the name of the person who described it
1809.
Answer: Yes, a lobster does have a brain, but it
is much different than a human's brain. The lobster "brain" is a
collection of cells in the "cerebral ganglion." The cerebral ganglion is
connected by a nerve cord to other ganglia located in the thorax and
abdomen.
Lobsters also have sensory systems equipped to respond to various changes
in their environment (e.g., light, pressure, chemicals, temperature).
Lobsters, and other crustaceans, may respond to stimuli with behaviors
such as withdrawal and escape. However, just because an animal responds
to a stimulus that we think is painful does NOT mean the animal is
experiencing pain. To illustrate this: a person who is anesthetized for
surgery may still withdraw his or her hand when pinched. Although this
person moved his or her hand, he or she did NOT feel any pain. This is
caused by the flexion reflex that is a spinal cord reflex...the brain is
not necessary for this response to occur.
The behavior of an animal may give us some clues about pain. In humans, an
injury usually results in pain. However, many invertebrates go about
their business (moving, feeding, mating, etc.) in a normal way after an
injury. For example, some invertebrates can lose a limb without showing
any change in behavior. To many scientists, this indicates that these
animals do not feel pain like humans.
Finally, the part of the brain responsible for the conscious perception
and emotional significance of pain, the cerebral cortex, is absent in the
lobster. Therefore, in my opinion, it is very unlikely that lobsters
experience pain in the same way as humans. Exactly "what" they "feel" is
a question that remains unanswered.
More about the invertebrate nervous system.
Answer: The cerebral aqueduct (also called
the aqueduct of Sylvius) connects the third and fourth ventricles.
Answer: Yes, feel free to create a link to
Neuroscience for Kids from your new site. The best URL to use is:
Answer: In 1909, German scientist Korbinian
Brodmann published a map of the cerebral cortex. On this map, he divided
the cortex into 52 different areas based on the characteristics of the
tissue (e.g., the density of the neurons; the thickness of the cortex; the
types of cells). The numbers associated with his map refer to the order
in which he studied the different areas. [Picture of Brodmann's Areas]
Answer: In humans, the neocortex accounts for 76%
of the total brain. For other animals:
Sperm Whale: 87%
Answer: The scientific name for earwax is
"cerumen." There are specialized wax secreting glands (called "ceruminous
glands") located in the ear canal. These glands make earwax. Earwax
keeps the eardrum (tympanic membrane) soft and waterproof. Earwax also
prevents small objects from reaching the tympanic membrane.
Answer: No. MAO (monoamine oxidase) is not a
neurotransmitter. MAO is an enzyme that destroys monoamine
neurotransmitters such as dopamine, norepinephrine and serotonin.
Answer from Dr. Chris B. (anesthesiologist and
Neuroscientist Network member): Norepinephrine released by the
sympathetic nervous system causes vasoconstriction and acetylcholine
released by the parasympathetic nervous system cause vasodilation. This
is independent of the cause (e.g., exercise, embarrassment, etc.) and is
the primary short term control of vascular tone. There are also mechanical
causes, e.g., "trauma" (for example, gently thumping on a vein will cause
it to dilate, thumping on an artery will cause it to constrict) which are
not mediated by neurotransmitters. A number of circulating compounds can
cause constriction and dilation, e.g., histamine, bradykinin, are
vasodilators while angiotensin and epinephrine are constrictors. The
former two are not generally involved in vascular tone except in
pathologic circumstances, e.g., bee sting, allergic reaction, anaphylaxis.
In contrast, angiotensin plays an important role in the kidney's longer
term control of blood pressure and epinephrine (adrenalin) is released by
the adrenal gland under certain conditions, e.g., fright, (this is one of
the reasons your heart beats faster when you are scared (sometimes known
as the "fright or flight response."
Answer: Yes, they do, but their brains are not
very big. Prawns and shrimp do have a centralized collection of nerve
cells that can be considered to be a brain. Description of the
brain of crustaceans (crabs, shrimps, lobsters, etc.).
More about the Invertebrate Nervous System.
Answer: Capoten is used to control high blood
pressure. This drug comes from the venom of a Brazilian pit viper, the
jararac snake (Bothrops jararaca).
Answer: Two answers from the Neuroscientist
Network:
The microglia serve as the "immune" type cells of the CNS. They appear to
possesses phagocytic properties and probably globulin production
capability as well. They are involved in immune-related activity of the
CNS and provide the first line of defense to a CNS infection from within.
Whenever the brain is faced with an infectious process, it must come from
outside of the CNS, thus the rest of the body is involved and as the
infectious process develops, it produces alteration in the BBB
functioning. Some viral infections can gain entrance to the CNS via
transport through neurons in the periphery, thus avoid the BBB. These
types are usually pretty devastating and very difficult to treat. In
these cases, it is up to nature, through the microglia to protect us.
Unfortunately, it often doesn't work so well (e.g., viral encephalitis,
herpes, HIV).
Answer: GABA is synthesized from glutamate by an enzyme
called glutamic acid decarboxylase. To work properly, this enzyme needs a
cofactor called pyridoxal phosphate.
Answer: The lyrics to "Telegraph Line" are still
on the Brain Songs page, but the audio and
video are not. The web site that I had linked to with the audio and video
is no longer working so I removed the link and have been unable to find a
new one. "Telegraph Line" is available on video. It's on "Science Rock.
School House Rock," produced by Scholastic Rock, Inc. You may be able to
find it at your local library.
Answer: The amount of time depends on several
factors such as how much a person has smoked, how long a person has smoked
for, and the method used to detect THC or its
metabolites.
Marijuana can be detected in urine, blood and saliva using methods called
thin layer chromatography, high pressure liquid chromatography, gas
chromatography, enzyme immunoassay and radioimmunoassay. The most
psychoactive ingredient in marijuana is delta-9-tetrahydrocannabinol
(THC). THC is broken down into several other compounds that are also
psychoactive. The half-life of THC is about 24 hours. However, the
metabolites of THC can be detected for 45 to 60 days after the last
use.
Here is some additional information that may be useful (from Maistro et
al., Drug Use and Misuse, 1991):
Answer: No. Some animals have taste receptors
(chemosensors) on their feet (e.g., butterfly and blowfly) or even over
their entire bodies (e.g., catfish and earthworm). The tongue of the snake
has no taste receptors.
Answer: According to the CDC:
The World Health
Organization (WHO) states: Answer: It might surprise you to find out
that humans do not have the largest brain weight to body weight ratio.
According to Dr. W.H. Calvin, in his book The River That Flows
Uphill, the squirrel monkey has a larger brain to body ratio (1 to 31
or about 3.2%) compared with that of humans (1/49 or about 2.0%).
An article published in Natural History (December 1999-January 2000 issue)
states:
The hummingbird also has a larger brain/body ratio compared with that of
humans.
An article published in Brain Behavior and Evolution (37:85-91, 1991)
states that the hummingbird has a brain mass of 228.85 mg and a body mass
of 5,970.38 mg. This means that the brain-to-body ratio of a hummingbird
is about 3.8%.
So, there is difference in opinion. One source says that the squirrel
monkey has a brain/body ratio of 3.2% and another says 5%. Another source
says that hummingbirds have a brain/body ratio of 3.8% which falls in the
middle of the two values given for the squirrel monkey.
Answer: I have two different Jell-O brain molds:
one shows the top half of the brain and the other shows a lateral view of
the brain. There are several places where you can buy these molds:
Answer: Some of the chemicals in nail polish that
can harm you are formaldehyde, toluene, ethyl acetate, butyl acetate and
isopropyl alcohol.
Answer: Yes, there are several studies that have
examined the brains of old polar bears for signs of Alzheimer's disease.
Several zoos, including those in Toledo, Denver, Knoxville, Royal Oak, Tacoma
and Baltimore, have participated in these studies. For summaries of this
research, please see:
Answer: The National Institute of Neurological
Disorders has a large
list and the Dana Alliance has a collection of neurological disorder
support groups in a publication called Brain
Connections.
Answer: Barrington's nucleus is a group of neurons
located in the brain stem near the pons. Neurons in this area project to
spinal cord neurons that then connect to the bladder.
Answer:
The terms neocortex, paleocortex and archicortex refer to their
phylogentic nature. Archicortex is the oldest, paleocortex is more recent
and neocortex is the most recent. You may also run into the term
"allocortex." Allocortex is divided into the paleocortex and archicortex.
Another difference is the number of cortical layers found in these areas:
neocortex has 6 layers; paleocortex and archicortex have only 3 layers.
Most of the cerebral cortex in humans is neocortex. Paleocortex is found
on the inferior and medial aspects of the temporal lobe (rostral insular
cortex, piriform cortex, primary olfactory cortex); archicortex is found
in the hippocampus.
Answer: No. The spinal cord contains
approximately 1 billion neurons (from Kalat, J.W., Biological Psychology,
6th Edition, 1998, page 24) and the auditory nerve contains 28,000 to
30,000 nerve fibers.
Answer: According to "The Joy of Cooking"
cookbook:
"So-called white chocolate contains no chocolate at all but is prepared
from vegetable fats, coloring and flavors."
White chocolate products are made with cocoa butter, the oil that is
pressed out of cocoa. Some resources that I found state that cocoa butter
has no caffeine. However, According to "The World of Caffeine" by B.A.
Weinberg and B.K Bealer (2001) and the International Cocoa
Association, cocoa butter DOES contain caffeine.
Answer: No...there is only one pineal body, one
pituitary gland, one third ventricle and one fourth ventricle. Some
midline nuclei of the thalamus and the more obscure interpeduncular
nucleus (in the midbrain) span the midline and do not actually have a
left and right side. "Broca's area" and "Wernicke's area," two cortical
areas important for language, are found only on one side (on the left for
most people). Most structures are found on both sides.
Answer: According to "The Handy Science Answer
Book" compiled by the Science and Technology Department of the Carnegie
Library of Pittsburgh (1994) there are 50 to 75 trillion cells in the
human body. However, others
estimate the number to be as high as 100 trillion. (Note: there are
about 100 billion nerve cells [neurons] in the human brain.)
Answer: According to the Monitoring the Future survey
released in December, 2003:
4.5% of 8th graders reported that they smoke daily.
Answer: Here are a few ideas:
Answer: You can spend anywhere from about $3.00 to
$600.00 for a brain model. Here are some choices:
Answer: The Dana
Alliance has a GREAT publication called Brain
Connections that lists the addresses, phone numbers, e-mail
addresses and URLs of many different patient support groups.
Answer: No. Axons and dendrites are not organelles
of a neuron. Think of axons and dendrites as arms and legs. Arms and
legs are part of the body, but they are not organs. Axons and dendrites
are part of a neuron, but they are not organelles.
Answer: The sciatic nerve is the longest nerve in
the human body. It is made up of nerve fibers that branch from the lower
spinal cord and extends down the leg.
Answer: Birds do have taste buds and can taste.
Taste buds are found in greatest number on the caudal surface of the
tongue, pharyngeal floor and in association with salivary gland openings.
However, in comparison with other animals, birds have very few taste buds
and therefore their sense of taste is probably not as good as other
animals. Here are some numbers for comparison (from G.C. Whittow [ed.],
Sturkie's Avian Physiology, Fifth Edition, San Diego: Academic
Press, 2000 and A.S. King and J. McLelland [eds.], Form and Function in
Birds, vol. 3, London: Academic Press):
Answer: Too much potassium in the extracellular
fluid can cause the heart to dilate and become weak and can even cause
death. Potassium can slow the heart rate and block cardiac impulses
from the atria to the ventricles. The reason for this is that high
extracellular concentrations of potassium reduce the resting membrane
potential of cardiac muscle fibers. This causes a reduction in the
intensity of the action potential and weaker heart contractions. If the
the extracellular concentration of potassium is great enough, the resting
membrane potential will be eliminated and cardiac muscle cells will not
generate impulses. Therefore, the heart will stop.
Answer: Valium (diazepam) belongs to a class of
drugs called the benzodiazepines. These drugs have their effects by
enhancing the activity of GABA receptors on neurons. More specifically,
they enhance the activity of a subclass of GABA receptors called the
GABA-A receptors. When activated, GABA-A receptors open chloride
channels. This causes hyperpolarization of neurons and neuronal
inhibition. The effects of valium are thought to act on GABA-A receptors
in the limbic system of the brain, especially in an area called the
amygdala.
Answer: 2-deoxyglucose (2-DG) is a molecule with
a structure very similar to that of glucose. Glucose, as you may know, is
the fuel for the brain. Areas of the brain that are more active, use more
glucose. The 2-DG method was pioneered by Sokoloff and associates in the
late 1970s to identify areas of neuronal activity. When 2-DG is injected
into an animal, it is taken up by regions that are metabolically active.
However, 2-DG is NOT COMPLETELY metabolized like glucose and it remains
within neurons. Therefore, when 2-DG is labeled with radioactivity, it
can be localized in the tissue using a histological method called
autoradiography. In this way, 2-DG gives a picture of brain areas that
were active.
Answer: G-proteins are involved with a specific
type of receptor (metabotropic receptor) that controls ion channels.
These receptors are located near G-proteins on the neuron membrane. When
a neurotransmitter molecule binds to a receptor, it activates the nearby
G-protein. This causes the G-protein to change shape and part of it
breaks off to bind to a site on an ion channel. This binding causes the
ion channel to open up. Another way G-proteins work is to activate
enzymes. When G-proteins activate enzymes, they cause the production of
second messengers. The second messengers then bind to ion channels to
open them up.
Answer: PROBABLY. Sleep can be defined in several
ways. One way sleep is defined is as a period of rest and inactivity.
Of course, because fish do not have eyelids, they can't close their eyes
during rest. If your definition of sleep is a period of rest and
inactivity, then "Yes, fish sleep" at least some species. It is very
difficult to record brain wave patterns from fish for long periods of
time, and even if you could record an electroencephalogram (EEG) the
"sleeping" brain patterns in fish would probably be different from other
animals because of differences in brain structure. However, many fish have
rest/activity cycles that indicate "behavioral sleep." EEG recordings
from the catfish have been made. These data showed differences in the
brain wave patterns during waking and behavioral sleep.
Campbell and Tobler (1984) published a paper that described sleep in many
different animals including bees, cockroaches, fish, amphibians, reptiles,
birds, and mammals. This paper states that some species of fish show
brief periods of rest while others are continuously active. The parrot
fish is one fish that shows interesting "sleep" behavior: it forms a
mucous cocoon in which it rests throughout the night.
(Reference: Campbell, S.S. and Tobler, I., Animal sleep: a review of
sleep duration across phylogeny. Neuroscience & Biobehavioral
Reviews, 8:269-300, 1994)
Answer: The enamel of the
tooth is the hardest
material in the body. The enamel is the outermost part of the
tooth; it covers the tooth crown.
Answer: Unipolar neurons are not very common in
vertebrates (they are more common in invertebrates). However, in
vertebrates, unipolar neurons are found in the ganglia of the autonomic
nervous system.
Pseudounipolar neurons are found in the dorsal root ganglia.
Bipolar neurons are found in the retina and olfactory epithelium.
Multipolar neurons are the most common of these types in vertebrates.
They are found all over the brain and spinal cord. Some examples:
spinal motor neurons, in the hippocampus, pyramidal neurons of the
cerebral cortex, Purkinje cells of the cerebellum, granule cells.
Answer: No. Babies are born with functional taste
buds. Several studies have actually looked at taste buds in the human
fetus. Taste buds have a non-gustatory (not taste) function from the 8th
to 14th week of gestation. After the 14th week of gestation, taste pores
are present and they probably develop their taste function at this
time. Taste buds are fully functional by about the 15th week of
gestation.
Answer: The gyri longus (long gyri) and gyri
brevis (short gyri) are located
on the surface of the insula. The insula is an area of cerebral cortex
that is buried within the lateral sulcus.
Answer: The septum pellucidum is a double-layered
structure that extends from the corpus callosum to the fornix. It is made
up mostly of glial-like cells and separates the right and left lateral
ventricles. The word "septum" comes from the Latin word for "wall" and
"pellucidum" comes from the word meaning "translucent."
The uncus is located on the anterior part of the hippocampus gyrus (on the
base of the brain). The uncus receives olfactory information. "Uncus"
comes from the Latin word meaning "hook."
Answer: Some authors use "brainstem," others use
"brain stem." In Principles of Neural Science by Kandel, Schwartz
and Jessell (McGraw Hill, 2000), it is "brain stem." Physiology of
Behavior by Carlson (Allyn and Bacon, 1998), The Central
Nervous System by Brodal (Oxford, 1998), Human
Neuroanatomy by Carpenter and Sutin (Williams and Wilkins, 1983) and
Dorland's Illustrated Medical Dictionary also
use "brain stem." However, in
Neuroscience by Purves et al. (Sinauer, 1997) and The American
Heritage Dictionary, it is "brainstem."
Answer: Some people who suffer damage to the
temporal lobe lose their ability to recognize and identify familiar faces.
This disorder is called prosopagnosia.
Answer: No, it is not true. According to the text
General Ophthalmology (Vaughan, Asbury and Riordan-Eva, Appleton &
Lange, Stamford, 1999), the size of the eyeball at birth averages 16.5 mm
in diameter (front to back measurement). In adults, the diameter is 24.2
mm. They go on to say that maximum eye size is reached when a person is
7-8 years old.
Other facts about the developing eye:
Answer: The tegmentum refers to the ventral part
of the midbrain. Structures in the tegmentum include the red nucleus,
substantia nigra and periaqueductal gray.
Answer: First, some definitions (according to
Kandel et al., Principles of Neural Science, 2000):
Beta wave frequency = 13 to 30 Hz
These names can get confusing because they do not follow a logical order
of the Greek alphabet. The brain waves were named not for their
frequencies, but for WHEN they were discovered. In other words, they have
historical significance, not functional significance. According to the
text Electroencephalography by Niedermeyer and Lopes Da Silva
(1993), the terms "alpha" and "beta" waves were introduced by Berger in
1929. So, these were the first two types of brain waves identified.
The term "gamma" wave was used for a short time for very high frequency
brain waves, but this term was abandoned. In 1936, Walter introduced the
term "delta" and he added "theta" for those brain waves between 4-7.5 Hz.
Walter skipped the Greek letters between delta and theta (epsilon, zeta
and eta) and used theta because he thought theta waves were generated in
the thalamus.
Answer: Yes, there will be BAW in the future.
Here are the dates for upcoming Brain Awareness Weeks:
March 14-20, 2005
Answer: You may be thinking of Baby
"Albert." Albert was an 11-month-old boy who was in an experiment
conducted by American psychologist John B. Watson. Watson was doing an
experiment on emotional response conditioning. At first, Albert liked
playing with a white rat. Later when Albert saw a rat, the experimenters
made a loud noise. This frightened Albert. After a few more times of
pairing the rat with the loud noise, Albert became frightened of just
seeing the rat.
Later on, Albert's fear generalized to anything furry like a rabbit, a fur
coat and dogs. This "experiment" was done many years ago (Watson, J.B.
and Raynor. Conditioned emotion reactions. Journal of Experimental
Psychology, 3:1-14, 1920) and such an experiment would be considered
unethical these days.
Answer: According to The Handy Science Answer
Book (1994) compiled by the Science and Technology Department of the
Carnegie Library of Pittsburgh:
Answer: The mammal with the largest brain is the
sperm whale. The brain of the sperm whale can weigh as much as 20 pounds.
Even though the blue whale has a larger body size, the blue whale brain is
about 5 pounds lighter than that of the sperm whale.
Answer from Dr. Chris B. (anesthesiologist and
Neuroscientist Network member): Awareness during surgery and
anesthesia does occur but is an extremely rare event. The anesthetic does
not "wear off" as the story may have suggested (as an aside, in my
opinion, medical/science stories are reported poorly by the media and are
frequently inaccurate because the media is selling sensation and not
fact. In addition, physicians and scientists are also culpable because
they are willing to make their work sound more
dramatic/important/sensational than it really is).
Anesthetics are given continuously during the surgery but very rarely the
amount given may not be sufficient to produce complete unconsciousness.
This occurs for two reasons; 1) by far, the most common reason is that the
patient does not tolerate the anesthetic (all anesthetics depress the
cardiovascular system) and the anesthesiologist has to turn the anesthetic
down to prevent it from depressing the blood pressure to dangerous levels.
This occurs most commonly in patients who are victims of severe trauma and
are rapidly loosing large volumes of blood. 2) awareness can also occur
in patients with a history of alcoholism, sedative/hypnotic abuse (e.g.,
valium, barbiturates, sleeping pills) because their brains are "resistant"
to the sedative effects of the anesthetic.
It should be noted that awareness is distressing, but patients usually
state that pain was not a problem for them, rather it was the distress
of being aware but unable to move for some reason they do not understand.
The reason they can't move is that they were given a "muscle relaxant"
which temporarily paralyzes the muscles. This is done to make it easier
for the surgeons to spread muscles (e.g., abdominal muscles) thus making
it easier to expose the surgical site. At the end of surgery, before the
patient is awakened, the muscle relaxant is reversed.
This question affords another interesting opportunituy to see how the
media and business are increasingly intertwined. The story you saw was
most likely the result of an ADVERTISING campaign for a device made by
ASPECT Medical (called the BIS) which they claim is capable of detecting
awareness. To sell this product they need to create a market.
Anesthesiologists have no interest in it because awareness is not a
significant problem (i.e., it is extremely rare and thus there is not much
reason to spend money using this device on millions of patients who are
not at risk of awareness) and this device has NEVER BEEN PROVED TO DETECT
AWARENESS. Thus, to make money the company is basically marketing it to
patients by first telling them (through "stories" like the one you saw)
that awareness is a terrible problem (and needlessly scaring them) but
fortuantely they have a solution. Consequently, patients come to their
anesthesiologists requesting that they use this unproved, useless,
expensive device during their anesthetic. Anesthesiologists are thus
"compelled" to buy this instrument to make their patients content.
Consequently, medical costs go up, but that is not a problem for ASPECT
because they reap the financial rewards.
Answer: Here are several pages of interesting
facts that should help:
Answer: The disorder you are probably thinking of
is called Werner's Syndrome. For more about this disorder, please see:
Answer: Perhaps this is the paper you were looking
for: Smith, S.M., Brown, H.O., Toman, J.E.P., and Goodman, L.S., The
Lack of Cerebral Effects of d-Tubocurarine, Anesthesiology, Vol. 8,
No. 1, (January, 1947) pp. 1-14.
Answer: MAO (monoamine oxidase) is an enzyme that
breaks down the class of neurotransmitters called the catecholamines.
MAO inhibitors are drugs that block the action of MAO and raise the
catecholamine content within neurons. These drugs are used to treat
depression.
Tyramine is an amino acid found in foods such as cheese, fish and
alcoholic drinks. Tyramine activates the sympathetic nervous system.
Moreover, the action of tyramine is blocked by MAO. Therefore, in the
presence of MAO inhibitors the action of tyramine is intensified and
prolonged. This may result in dangerous hypertension and even cerebral
hemorrhages.
Answer: There are over 600 skeletal muscles in the
human body. Anatomists disagree on the exact number of muscles.
Skeletal muscle makes up about 40% of total body weight. Also, the saying
"It takes more muscles to frown than to smile" is true: you use 43
muscles to frown and only 17 to smile.
Answer: Sleep deprivation IS a huge problem not
only for students, but for adults as well. I will refer you to some
sources of information concerning later school start times and some
schools that have made the switch to later start times. Please see:
Answer: Reuptake refers to the process by which a
neurotransmitter is transported back into a neuron's synaptic terminal.
In other words, after a neurotransmitter is released, it floats into the
synaptic cleft. One mechanism that stops the action of neurotransmitter
is by transporting the neurotranmitter out of the synaptic cleft back into
the terminal.
Answer: Dr. Leo H. Sternbach of Hoffmann-La Roche
(Roche in the 1950's).
From L.H. Sternbach's chapter entitled "The Discovery of CNS Active
1,4-Benzodiazepines" in the book "The Benzodiazepines: From Molecular
Biology to Clinical Practice" edited by E.Costa, Raven Press, New York,
1983:
This information is confirmed on the Hoffmann
La-Roche web page (scroll down a bit).
Answer: (from Dr. Chris B., Neuroscientist
Network member) The
phenomenon results from hypoperfusion of the brain, particularly the
occipital cortex. But I do not know why one sees "stars" as opposed to
something else. Hypoperfusion results because standing up too rapidly can
result in a decrease in venous return so the heart is not as full as
necessary to maintain adequate cardiac output.
Answer: (from Dr. Ed F., Neuroscientist Network
member) Orthostatic hypotension, decreased blood flow to the brain
because of a gravitational pooling of the blood in the lower extremities.
The baroreceptor reflex minimizes this as it senses the decreased blood
pressure in the aortic arch and responds by sending a signal, through the
brainstem, to increase sympathetic tone in the blood vessels of the lower
legs. This results in a vasoconstriction and helps force more blood to
the upper part of the body.
This reflex is reduced in the elderly and by many medications. That is
why people, especially elderly and those on various heart, blood pressure
medications, antidepressants and any CNS depressant should get up slowly
from a lying or sitting position.
Answer: The effect of temperature is mainly on
ionic permeability of the neuronal membrane. Specifically, sodium
channels open and close faster at higher temperature. Reductions in
temperature lengthen the action potential and slow conduction
velocity...these are the classic experiments of Hodgkin and Katz
(1949).
Answer: Babies are born with between 300 to 350
bones. As people get older, some of these bones fuse together. Most
adults have 206 bones.
Answer: The cerebrum refers to the entire cerebral
hemispheres. The cerebral cortex is the outermost part of
the cerebrum.
Answer: Yes, physical exercise does appear to be
good for the brain. There are been several studies that show that exercise is
beneficial to the brain. In fact, there was a recent experiment in mice
that showed that running can increase the number of nerve cells in the
brain. For a summary of this research, see:
Answer: In my review of
the literature on the effects of the full moon on behavior, I found
that most studies show no relationship
between the phase of the moon and abnormal behavior.
In all of the background research and literature searches I conducted for
the Moonstruck article I did not find any papers that examined the
correlation between the phase of the moon and children's behavior. As I
discussed in the article, there are some problems in the design of these
studies in that they only determine that a correlation does or does not
exist between two variables (i.e., phase of the moon and a change in
behavior). They do not prove that the phase of the moon CAUSES a
particular behavior.
Answer: Ringing in the ears is called "tinnitus."
All of the causes are not well understood. Some forms of tinnitus are
caused by problems in the inner ear, such as damaged hair cells.
However, some forms may NOT have a peripheral origin. In other words, the
"ringing" may be in the brain, NOT the ear. For more about tinnitus,
please see:
Answer: Dopamine is a neurotransmitter (a
catecholamine type neurotransmitter). It is found in many places in the
central nervous system and has several functions including:
1. Movement: dopamine is produced in the substantia nigra (a part of the
basal ganglia). In Parkinson's disease, dopamine neurons in the
substantia nigra die. This disorder is characterized by tremor, rigidity
and slowness of movement. When the dopamine is restored in the brain by
giving L-dopa, the movement problems in many cases are reduced.
2. Attention: there is some evidence that dopamine is altered in people
with attention deficit disorders.
3. Emotional behavior: an overactive dopamine system may underlie
schizophrenia. Dopamine blocking drug reduce the symptoms of
schizophrenia.
4. Addictive behavior
Answer: The 5th basic taste is called "umami."
Umami is a taste that occurs when foods with glutamate (like MSG) are
eaten. More information on umami:
Answer: In "normal" cases, yes, the action
potential goes in only one direction: toward the axon terminal. However,
an action potential will spread in BOTH directions IF it is started in the
middle of an axon. This can be done by electrically stimulating the
middle of an axon. This is not the normal way action potentials are
triggered. Rather, an axon potential usually starts at the axon hillock
and sequentially depolarizes the neuronal membrane away from where it
started. That is why in normal situations it only travels in one
direction.
Answer (By Neuroscientist Network Member Dr.
P.):
a) Background
Catecholamines: This name refers to all organic compounds that contain a
catechol nucleus (a benzene ring with two adjacent hydroxyl residues), a
side chain of two carbon atoms (the b-carbon is closest to the ring, the
a-carbon is distal), and an amine (NH2) group bound to the a-carbon. The
word "catechol" is derived from "catechin," a crystalline substance
extracted from the spiny Asian tree "catechu" (Acacia catechu) which is
used in the preparation of tannins and other brown dyes. Catechin and
catechol are synonymous. In practice, the term catecholamine refers to
dopamine (DA, dihydroxyphenylethylamine) and its metabolic products,
norepinephrine (NE) and epinephrine (E).
b) Neurotransmitters
i. Dopamine (DA): The easiest explanation for dopamine's name is that it
is a selective compression of its chemical name,
dihydroxyphenylethylamine.
To better understand the nomenclature, we can start a couple steps back in
the pathway that leads to the formation of DA. The amino acids
phenylalanine or tyrosine can be the starting compound for the synthetic
pathway. If phenylalanine (a compound similar to the catechol structure
except there are no hydroxyl groups bound to the benzene ring and there is
a carboxyl group (COOH) bound to the same carbon containing the amine
group), an enzyme, phenylalanine hydroxylase, adds an hydroxyl group to
the benzene ring. This product is tyrosine which can also be provided in
the diet directly. The next step in the pathway involves the enzyme
tyrosine hydroxylase, the rate limiting step in the entire process, which
adds a (second) hydroxyl group to the aromatic ring. The resultant
compound is "DOPA" (dihydroxyphenylalanine), a compound with a catechol
backbone as described above. The final step in the synthesis of dopamine
involves the removal of the carboxyl group from the two carbon side chain
of DOPA by the enzyme DOPA decarboxylase. Thus dopamine is composed of the
basic catechol backbone (dihydroxyphenylethylamine) with no substitutions
on the two carbon side chain.
ii. Norepinephrine (NE): Once we've learned how dopamine is formed, the
related catechol compounds fall easily into place. Norepinephrine is
formed from dopamine through the activity of the enzyme
dopamine-b-hydroxylase. Norepinephrine is simply dopamine with an hydroxyl
group added to the b-carbon of the two carbon side chain. See Epinephrine
for the word derivation.
iii. Epinephrine (E): The enzyme phenylethanolamine-N-methyltransferase
adds a methyl group to the amine (NH2) bound to the a-carbon of
norepinephrine.
The derivation of the names epinephrine and norepinephrine are most likely
related to the locale of the highest concentration theses substances: the
adrenal glands. Because the adrenals sit atop the kidneys, the word
epinephrine can be parsed logically: "epi-" means "upon or close to,"
"nephr" is the contraction of "nephro," a prefix designating the kidney,
and "ine," a suffix given to many chemical compounds. The prefix "nor"
designates an unaltered parent compound. This suggests that norepinephrine
was isolated subsequent to epinephrine and, upon discovery of the
relationship, was named appropriately. The parallel nomenclature of
"adrenaline" and "noradrenaline" provide a more obvious derivation.
Serotonin was named, shortly after its discovery, for its ability to cause
powerful contractions of smooth muscle. Thus it was considered a major
component in the serum responsible for vasoconstriction and high blood
pressure. 2) Acetylcholine is straightforward, formed as product of the
enzyme choline acetyltransferase.
Answer: According to the Sleep Well web site
(Stanford University Sleep Center):
K.A.: What would happen if two action
potentials coming from opposite directions collide? Would they sum up
to a specific point or would they cancel each other out?
N.V.: What is the width of the spinal cord?
Midthoracic area (sagittal diameter) = 8 mm
Cervical enlargement (transverse diameter) = 13-14 mm
Cervical enlargement (sagittal diameter) = 9 mm
Lumbar enlargement (transverse diameter) = 12 mm
Lumbar enlargement (sagittal diameter) = 8.5 mm
L.H.: What is the origin of the word "ballismus?"
P.R.: What is the difference between gray matter and
white matter?
A.C.: What is the purpose of the knee jerk reflex?
E.B.:Does the drug Ecstasy (MDMA) affect women and men
differently?
A.A.: For how long can drugs be detected after you take
them?
P.W.:
I am looking for a list of (brain) neurological disorders to use as a
reference for students doing research projects.
A.K.:How many people die each year from smoking?
D.K.: Can using methamphetamine cause vision problems?
C.L.: While sitting in a chair, move your right leg in a
clockwise motion. At the same time, try to draw a "6" in the air with
your right hand. This is difficult to do! Why?
Alex A.: What is the difference between a tract and a nerve?
M.N.: Where can I buy a cookie cutter in the shape of a
brain?
S.M.: Do fish have tongues?
S.C.: What are the 10 most elements in the human body?
Oxygen - 65%
Carbon - 18.5%
Hydrogen - 9.5%
Nitrogen - 3.3%
Calcium - 1.5%
Phosphorus - 1.0%
Y.D.: What is a beta-blocker?
T.M.: What is the average salary for a new Neuroscience
graduate? ?
Postdoctoral Years Yearly
of Experience Salary
------------------- ------
0 $ 34,200
1 $ 36,108
2 $ 40,920
3 $ 42,648
4 $ 44,364
5 $ 46,404
6 $ 48,444
7 or more $ 50,808
A.N.: Is MDMA the same thing as Ecstasy?
Nancy M.: What drug is called "Doves?"
Amy S.: Do ears continue to grow as we get older?
H.R..: When did J. Ridley Stroop invent the Stroop Test?
D.B.:
I was doing some research on where Einstein's Brain was located and had
heard that it was in a basement in New Jersey. Is this true?
B.K.:
Do people who have had a "split brain" operation dream?
N.C.:
What type of glial cell is more common:
astrocytes or oligodendrocytes?
S.G.:
What is a curare and how does it work?
D.C.:
Are you aware of any place on the Internet where I could get more info
(and pictures) about the incredible surgery performed on the separation of
the twins, joined at the skull?
Marco A.: How much time does a penguin spend sleeping?
(Reference: Buchet C, Dewasmes G, Le Maho Y., An
electrophysiological and behavioral study of sleep in emperor penguins
under natural ambient conditions, Physiology and Behavior,
38(3):331-335, 1986.)
M.D.:
Can a person get marijuana in their system from being in a car while
other people are smoking? Have there been any studies about this?
Derrick C.: Are there muscles in the brain?
C.H.:
If someone who cannot hear is deaf, and someone who cannot see is blind,
what is it called if people cannot smell or taste?
Martin
S.:
Was Otto Loewi from Germany?
T.P.:
How big is a dolphin brain?
R.F.:
Do bees have taste buds?
Erickson, Jr., E.H., Carlson, S.D. and
Garment, M.B.,A Scanning Electron Microscope Atlas of the
Honey Bee, Iowa:Iowa State University Press, 1986
Seeley, T.D., The Wisdom of the Hive: the Social Physiology of Honey
Bee Colonies, Cambridge: Harvard University Press, 1995
P.R.:
Will you direct me to a source or advise me on the amount of WATTS
of electricity generated by the brain?
A.B.:
When a skull is preserved, why doesn't it have a nose and ears?
A.B.:
Is it true that a certain amount of dried cockroach is allowed in making
chocolate?
K.D.:
How many pairs of spinal nerves does a cat have?
A.B.:
Which cranial nerves are part of the autonomic
nervous system?
A.K.:
I know that people can see and hear things during dreams, but can people
smell things too?
D.R.:
What is the difference between an independent variable and a dependent
variable?
F.A.:
What part of the pufferfish concentrates tetrodotoxin?
I.B.:
Do giraffes have the same number of neck bones as humans?
S.B.:
What is the island of Reil? I have not been able to find anything about
it. How, when, and why did it get this name?
B.S.:
Do lobsters have a brain? Do lobsters feel pain like humans do?
Mike:
What connects the third ventricle to the fourth ventricle?
L.H.:
I am making my own web site. Is it alright if I make a link on my site to
Neuroscience for Kids?
http://faculty.washington.edu/chudler/neurok.html
Mike:
What are Brodmann's Areas?
T.R.:
What is the ratio of neocortex to total brain size in humans and other
animals?
Chimpanzee: 72%
Monkeys: 55-60%
Rodents: 40-50%
Platypus: 48%
Marsupials: 20-30%
Insectivores: 10-20%
(Reference: Nieuwenhuys, R., Ten Donkelaar, H.J. and
Nicholson, C., The Central nervous System of Vertebrates, Vol. 3,
Berlin: Springer, 1998)
A.S.:
How does earwax get in your ears?
M.H.:
Is MAO a neurotransmitter?
Ian
D.:
What are the substances that cause the blood vessels in the skin to dilate
and constrict? Are there different substances according to the stimulus
that caused the vessel change (e.g., exercise, embarrassment, irritation,
food)?
Nicole
F.:
Do prawns have brains?
Tori:
I was watching the Discovery Channel the other day and something caught my
eye and I have been wondering about it ever since. I think they said that
a venomous snake in Brazil is used to make a drug called Capoten. Can you
give me some information on this?
J.K.:
Can
antibodies cross the blood-brain barrier (BBB)? How does the body fight
infections in the brain?
A.C.:
What is the precursor of the neurotransmitter called GABA?
T.E.: I
have visited your web site many times in the past. I once found the song
"Telegraph Line" about the nervous system on your site, but I can't find
it anymore. Do you still have it? I wanted to use the song with my
students.
J.J.:
How long does THC stay in your body after you use marijuana?"Approximately half of the THC is excreted over several days,
and the remainder by the end of about a week. However, some metabolites
of the THC, a number of which may still be active in the system, can be
detected in the body at least thirty days following ingestion of a single
dose and, following chronic use, in the urine for several
weeks."
D.R.:
Do all animals have taste receptors on their tongues?
C.T.: How many people die each year from
smoking?
"An estimated 46.5 million adults in the United States smoke cigarettes
even though this single behavior will result in death or disability for
half of all regular users. Cigarette smoking is responsible for more than
440,000 deaths each year, or one in every five deaths."
"Smoking is estimated to have caused around three million deaths a year in
the early 1990s, and the death toll is steadily increasing."
From
E.H.: What animal has the largest brain compared to its body
weight?
"Pound for pound, the record for brain size is
probably held by fruit-eating squirrel monkeys (genus Saimiri) of South
America, whose brain account for 5 percent of their body weight, on
average."
From
Liza A.: Where can I buy a Jell-O (gelatin) brain mold?
From
M.R.: I know that nail polish should not be sniffed. What are
the
dangerous chemicals in nail polish?
From
E.K.: Is this true? Some researchers searching for a cure for
Alzheimer's disease find the study of polar bear brains useful because their
brains are similar to human brains. I heard that when geriatric polar bears
die in zoos that their brains are studied for lesions related to
the aging process.
From
M.G.: Where can I find a list and description of disorders that
affect the nervous system?
From
Peter C.: What is Barrington's nucleus?
From L.
T.: What is the difference between neocortex, paleocortex and
archicortex?
From
Cyrus: Does the ear have more nerves than the spinal cord?
From S.P.:
Does white chocolate have caffeine?
From
M.L.:
Do all structures of the brain have a right and left side ?
From
M.B.: How many cells are in the human body?
From
E.Z.: How many kids smoke each day?
8.8% of 10th graders reported that they smoke daily.
15.8% of 12th graders reported that they smoke daily.
From
Marilyn P.: I am looking for a video of about half an hour
that
explains brain function, learning, research done using MRI's or anything
of a similar nature. I am hoping you can recommend a video that I can
get within a couple weeks.
From
N.M.:
My daughter is studying cognitive brain science in college. She asked me
for a model of the brain because she felt it would help her in her
studies. Could you recommend what I should be looking for and where I
could purchase it?
From
A.A.: Do you have a list of organizations or agencies that have
information about different neurological disorders? I want my students
to write to these places for material.
From
A.G.: Are axons and dendrites organelles?
From
D.B.: What is the longest nerve in the human body?
From
R.H.: Do birds have a sense of taste?
Animal Total # of taste buds
------ ---------------------
Chicken 24
Bullfinch 46
Turtle Dove 54
Japanese quail 62
Pigeon 50-75
Starling 200
Mallard 375
Bat 800
Human 9,000
Pig 15,000
Rabbit 17,000
Catfish 100,000
Behavioral experiments have shown that some birds (parrots, hummingbirds)
prefer sweet tastes, but other birds (red-winged blackbirds) do not like
sweet tastes. Some birds even like bitter tastes.
From
K.B.:
Why is an intravenous injection of potassium chloride dangerous to the
heart?
From
S.T.: How does valium affect the central nervous system?
From Andrew
J.: What is 2-deoxyglucose and how does it work?
From
D.B.
How do G-proteins work?
From
A.T.: Do fish sleep?
From
Dennis M.: What is the hardest material in the body?
From
T.P.: Where are uniploar, bipolar and multipolar neurons found?
From Nora: Are babies born without taste buds?
(Reference:
Embryonic and early fetal development of human taste buds: a transmission
electron microscopical study.)
From
K.R.: Where are the gyri longus and gyri brevis located in
the brain?
From
P.F.: What are the uncus and septum pellucidum?
From
Tom B.: Is it "brainstem" or "brain stem?" Is it one or two
words?
From Linda
P.: What is it called when a person cannot recognize faces?
From
Pat: I heard that the eyeball was the only part of the
human body that is full size at birth. Is this true?
From
N.C.R.: What part of the brain is the tegmentum?
From
Anne S.: Can you tell me the origins of the brain wave names
(alpha, beta, theta, delta) and why they were chosen? They are
confusing!
Alpha wave frequency = 8 to 13 Hz
Theta wave frequency = 4 to 7 Hz
Delta wave frequency = 0.5 to 4 Hz
From
L.B.: Will there be more Brain Awareness Weeks in the
future?
March 13-19, 2006
March 12-18, 2007
From
Traci: I was wondering about the experiment with a baby
and a ringing bell. When the baby got older and heard the bell he
did the thing as when he was younger. Do you know the name of the
baby?
From H. and
C.: Approximately how many hairs are on one human head?"An average person has about 100,000 hairs on their
scalp."
From
Jerry H.: What mammal has the largest brain?
From Stephanie
S.: I heard something on the news a while ago. Here's the main
plot: Patients are anesthetized and are brought into surgery. However
during the surgery, the anesthesia wears off and the patients feel
everything that's happening to them. BUT they can't say anything or move
anything because they're paralyzed for some reason. I think the term for
this is "surgical awareness." Have you heard of this?
From
C., L. and E.: Can you give us some interesting facts about
the nervous system? We're doing a school project.
From
Sascha: What is the sickness that makes you age faster than
normal?
From
M.L.: I've been searching for a couple of weeks for a story
I've heard about but can't find a source for. Some researcher thought
that curare was an "anesthetic" so he tried it on himself.
Although paralyzed, he could still feel everything.
Do you know this antecdote?
From
M.J.: Why do people taking MAO-inhibitors have to be on a
tyramine restricted diet?
From
Carolyn.: How many muscles are in the human body?
From
K.H.: Do you have any information about sleep deprivation in
teenagers and school start times?
From
Phil W.: What is "reuptake?"
From
Robert A.: Who discovered diazepam?
"Near the end of 1959, we found a product that was, in most of the tests,
3 to 10 times as potent as chlordiazepoxide. We hoped that this superior
potency would be associated with other advantages in its clinical spectrum
of activity and selected it for a thorough evaluation. The
pharmacological and toxicological data looked very promising: the
clinical results were equally encouraging and led ultimately near the end
of 1963 to the introduction of diazepam, under the trade name
Valium."
From Scott
T.: Why after sitting down for a long time and you stand up
fast do you sometimes see light spots or stars?
From
Bonnie M.: What is the effect of temperature
on the shape of the action potential? From
Z.Z.: How many bones are in the human body? From
Laura M.: What is the difference between the cerebrum and
the cerebral cortex? From
G.J.: Do you think exercise is good for the brain?
From Debbie
G.: I have always heard a full moon will affect behaviors but
your page contradicts that myth. I have been teaching elementary school
for 19 years and I was wondering if there have been any case studies on
how a full moon affects children's behaviors. I don't keep track of when
it's time for a full moon, but I can usually tell by the way my students
act. From
Mark W.: What causes "ringing in the ears?"
From
J.M.: What is the function of dopamine in the brain?
From C.
Are there five basic tastes? I looked it up under ask jeeves and it only
gave me 4 ( sweet, sour, salty, and bitter.) What is the other one?
From
Sarah N.: Does an action potential go in only one direction?
From A.
N.: How did neurotransmitters get
their specific names? Such as, why is dopamine called dopamine? serotonin?
norepinephrine?
From
K.B.: How much sleep does a third grader need?"Adolescents need 9 hours and 15 minutes of sleep. Children
need 10 hours and adults need 8 1/4
hours."
More question/answer sites:
BACK TO:
Exploring the
Nervous System
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