Connectionist Learning - Some New Ideas

[Mark Johnson]

>One loses about 100,000 cortical neurons a day (about a percent of
>the original number every three years) under normal conditions.

Does anyone have a concrete citation (a journal article) for this or
any other similar estimate regarding the daily cell death rate in the
cortex of a normal brain?  I've read such numbers in a number of
connectionist papers but none cite any neurophysiological studies that
substantiate these numbers.

Thanks,
Raj
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