Welcome to the Neuroscience for Kids Newsletter.
Here is what you will find in this issue:
1. What's New on the Neuroscience for Kids Web Pages
2. The Neuroscience for Kids Page of the Month
3. Teacher/Student Events at the Society for Neuroscience Meeting
4. Wonders of the Sea
5. Close Encounters of a Rattler Kind
6. California Schools Fail on Pesticide Use
7. Book Review
8. Media Alert
9. Treasure Trove of Brain Trivia
10. How to Stop Your Subscription
A. August Neuroscience for Kids Newsletter was archived
B. September NeuroCalendar
C. The Location of Intelligence in the Brain...Found?
D. Get the Mercury Out! The Effects of Mercury on the Nervous System
E. Sleep May Enhance Memory and Learning
F. Nutrition and the Brain
G. Neuroscience Web Sites Interactive Tour (requires Shockwave)
In August, 40 new figures were added and 77 pages were modified.
The Neuroscience for Kids "Page of the Month" for September is "Human Brain Anatomy: Midsagittal Sections" from the Department of Psychology at the University of Alberta (Canada):
"Human Brain Anatomy" is an interactive tour of the structures that can be seen when a brain is divided in half by a midsagittal section. A midsagittal section separates the right and left hemispheres of the brain and is described in detail on the first page of the tour. The remainder of the tour discusses various brain structures as you build the brain from the spinal cord up to the cerebral cortex. Navigation through the tour is very easy and there are short quizzes to test your learning after each part of the brain is described.
You must have the free Shockwave plug-in to view "Human Brain Anatomy."
Enjoy the tour!
Many people spend much of their time at aquariums looking at large animals such as seals, otters, and sharks. Not me. I like the small ones: anemones, snails, sea urchins, crabs - all invertebrates. The chemical weapons that some of these little fellows use are amazing. Some marine animals use venoms that contain neurotoxins (chemicals that attack the nervous system) to protect themselves and to capture prey. For example, the cone snail uses a deadly neurotoxin called conotoxin. One type of conotoxin blocks a neuron's sodium channels, thus disrupting how messages in nerves are sent. Other marine animals that use neurotoxins include sea snakes, anemones, pufferfish and blue-ringed octopus.
Many marine neurotoxins are used by neuroscientists to study basic
functions of the nervous system. It is possible that cures and treatments
for neurological disorders may be discovered by understanding how these
venoms affect the brain.
Last month my Dad was walking in his backyard in Los Angeles when he heard the distinctive sound of a snake's rattle. When he saw the snake, he knew immediately that it was a rattlesnake. The timing could not have been worse because five of his grandchildren, all under the age of 8 years, were visiting for a few days. My Dad called the fire department which sent people to his house to kill the snake. In my opinion, it is unfortunate that they had to kill the snake rather than relocate it to a place where it could not harm people. Rattlesnakes play an important role in the ecosystem by eating small rodents.
Rattlesnakes are classified as pit vipers because they have a facial pit located between each nostril and eye. The facial pit contains heat sensitive receptors that allow the snake to locate its prey. It has been estimated that the receptors in the facial pit are sensitive enough to detect temperature differences of only 0.003 degrees centigrade. Rattlesnakes have another interesting sensory apparatus called the Jacobson's organ. Jacobson's organ is located in the roof of the snake's mouth. Scientists believe that the snake samples its environment with quick flicks of its tongue that bring air-borne molecules to the Jacobson's organ. Receptor cells in the Jacobson's organ are connected to nerves that transmit information to the snake's brain.
The bites from most rattlesnakes in the Southern California area cause pain, tissue damage and blood clotting problems. The venom of some rattlesnakes is highly neurotoxic. For example, the venom of the South American rattlesnake contains crotoxin. Crotoxin prevents the release of the neurotransmitter acetylcholine. This causes muscular paralysis and when breathing muscles are paralyzed, a person can die. The venom of the Mojave rattlesnake also contains a neurotoxin that acts in a similar way.
It just goes to show that if you look around, you can find neuroscience just about anywhere...even in your backyard!
DID YOU KNOW? Venomous snakes can be dangerous even after they are dead. A study published in the New England Journal of Medicine (NEJM) reported that 14.7% of the people envenomed by rattlesnakes were bitten by snakes that were dead or thought to be dead. (Statistic from the New England Journal of Medicine, June 17, 1999, vol. 340:1930.)
Centipede in Hawaii story:
Pesticides that work by targeting the nervous system were used in 11 of the 13 school districts. Many of these pesticides are chemicals classified as cholinesterase inhibitors; they prevent the breakdown of the neurotransmitter acetylcholine. One of these chemicals, chlorpyrifos, a pesticide recently banned for many uses by the US Food and Drug Administration (FDA), was used in 8 of the 13 school districts.
CALPIRG also found that many school districts are not required to notify teachers or parents about pesticide application and do not even post notices about when and where spraying occurs. For the health and safety of students, teachers, and staff, it appears to me that some policies should be changed.
What about your school district? Do you know what pesticides are used? Do you know when and where they are used?
CALPIRG recommends that parents learn about the pesticide policies of their school districts and insist on notification about when and where pesticides are used. School officials are asked to use the least toxic pesticides and to prohibit the use of dangerous chemicals. For more about the CALPIRG report and additional recommendations on pesticide use, read the full report on-line at:
For more on the FDA chlorpyrifos ban, see:
"Brainbox" is intended for elementary school children interested in learning about the brain. Although students may enjoy this book with its many colorful drawings, there are a few factual errors that should be noted. For example, on page 6 in a discussion of how an axon splits into threads like roots, the authors write, "Each of these roots gently touches a dendrite of another nerve cell." As you may know, within a chemical synapse, two neurons do not actually "touch." Rather, there is a small space between neurons. The authors also incorrectly define the electroencephalogram as a machine that can read your brain waves. Actually, the electroencephalograph is the machine and the electroencephalogram is the record of brain wave activity.
Another misconception is in the discussion of the response to stepping on a pin (pages 10-11). The authors imply that after a person steps on a pin, the brain sends a signal to move the foot off the pin. Actually, the brain is not needed for this response; a built-in spinal cord reflex (flexion-withdrawal reflex) takes care of this job before the brain is aware of the pin. In fact, this response is performed even if the spinal cord is cut, completely isolating the brain from the spinal cord! The speed with which messages can travel within an axon is also reported in the book to be 50 meters per second. Actually, messages can travel at speeds ranging from 0.2 to 120 meters per second.
I wanted to like this book. I think it was a great idea for a
neuroscientist to team with a student on this kind of project. However,
the factual errors and lack of photographs in "Brainbox" prevent me from
recommending the book.
B. "Worrying about Wireless" in Scientific American (September, 2000). Another article on cell phones and brain cancer.
C. "Keith Black. Brain Surgeon of Last Resort" in Biography magazine, August, 2000, pages 58-61. Biography of neurosurgeon Dr. Keith Black.
D. "Tapping the Power of the Placebo" in Newsweek Magazine (August 14,
2000). The use of "sugar pills" and how they may be used.
B. In 1998, illegal drug use or nonmedical use of legal drugs resulted in 542,544 visits to emergency departments in the United States. (Statistic from the Drug Abuse Warning Network)
C. The three most common fears are: snakes (#1), heights (#2) and flying (#3). (Statistic from Health, "News for Healthy Living," Nov/Dec. 99, p.28)
D. The human ear canal is about 2.5 cm in length and 0.6 cm in diameter. (Statistics from "Hearing. Its Physiology and Pathophysiology" by A.R. Moller, San Diego, Academic Press, 2000.)
E. Each of your eyeballs is moved by six muscles.
Your comments and suggestions about this newsletter and the "Neuroscience for Kids" web site are always welcome. If there are any special topics that you would like to see on the web site, just let me know.
Eric H. Chudler, Ph.D.
"Neuroscience for Kids" is supported by a Science Education Partnership Award (SEPA) from the National Center of Research Resources.