Abolishing brain cells

molliebatmit
Wed, 18 Jun 2008 20:16:16 +0000

Would like to know how to enhance the regenerative process, and/or lessen the undesireable effects on neurons by x-rays, radiation, etc. Any clues, molliebatmit?

Well, the first thing is to stay away from radiation! (And if you want to read more about radiation’s effects on neurons, a recent paper is [here](Quiescent adult neural stem cells are exceptionally sensitive to cosmic radiation - PubMed).)

Nobody really knows how to keep neural stem cells young and happy, although my money is on things like exercise and healthy eating. And though (as mapesy’s link explains) exercise seems to stimulate birth/promote survival of newly-born neurons in the hippocampus, it’s not entirely clear why this is so.

If I had to give a hand-waving explanation, I would say that exercise raises levels of brain serotonin, and there’s some evidence linking excess serotonin to neuron birth and survival in the hippocampus – people who are depressed or have PTSD have small hippocampi, drugs like Prozac/Zoloft start to work on a scale that fits well with neurogenesis, and blocking neurogenesis in depressed mice blocks the function of antidepressants. But it’s not clear if the relationship is really causal, or why that would be so if it is causal.

Scientists are also still trying to work out exactly why certain populations of neurons die in diseases like Alzheimer’s, Parkinson’s, and Huntington’s. Very specific populations of neurons die in each of these diseases, but it’s not clear why.

I wish I had better answers for all of you, but these are big issues that are the focus of a lot of current research. Does anybody have an easy question I can answer about the brain? :)