Neurons, Neurotoxins, and the Forgotten Brain Cell
This excellent Web site provides a variety of useful information related to neurobiology, including; articles, links, and online multimedia activities. Check out the virtual tour of the nervous system. Tour a gallery of photographs of nerve cells. Compare the brains of different animal species. Travel through time and review the history of brain science. To get started, prepare answers to the following questions:
1. How many neurons are there in the average human brain? What features do neurons have in common with other cells in the body? In what ways are neurons unique? What's inside a neuron?
2. Did you know that neurons are the oldest cells in your body? Unlike other body cells, which routinely die and are replaced, neural cells are not replaced when they die. This means that you have fewer neurons as you get older, but the ones you have are the very same ones you were born with! Why do you think this is so? In other words, what evolutionary advantage does this "quirk" of neurons convey to our species?
3. The axons of neurons differ in the speed with which they conduct neural impulses. How many different basic neural speeds are there? Is there a relationship between the type of information conveyed by an axon and the speed at which it conducts?
4. What defensive weapon do spiders, snakes, scorpions, and some bees share in common? List three of these weapons and explain the effect of each on the neurons of a predator. How are these substances similar to nerve agents and other chemical weapons?
5. Why are glial cells referred to as the "forgotten brain cells?" State five ways that glia differ from neurons. What would happen to your behavior if your glia suddenly stopped functioning?