allens at yang.earlham.edu (Allen Smith) writes:
> In other words, the number of synapses (as opposed to brain cells)
>goes down as one gets older? Then why does "fixed" IQ increase with age?
>Is this decline simply due to loss of neurons, or what?
> If we're going to really stop aging, then we'll need to figure out
>how to get neurons to regenerate. Some clues can probably be found in the
>nasal neurons (which keep dividing); what's the current status of research
>on the cause of this difference?
> -Allen
Just to clarify, the basal cells of the olfactory
epithelium continue to divide in adults. The smell receptors
turnover about every 30-60 days in mammals. There's a recent
paper on olfactory epithelial cell dynamics (J. Neurosci. 11:979-984)
which might be of interest - also see the references therein.
I would be surprised if much is known about the factors
regulating this turnover.
- Michael Lyons