In a message dated 5/8/99 3:09:01 PM Eastern Daylight Time,
[EMAIL PROTECTED] writes:
> Subj: Neurons
> Date: 5/8/99 3:09:01 PM Eastern Daylight Time
> From: [EMAIL PROTECTED] (JL Edwards)
> Sender: [EMAIL PROTECTED]
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> How are neurons counted?
>
> JL Edwards
>
> [EMAIL PROTECTED]
>
Well, some years ago (c. late 1970's) we counted neurons mentally using a
caliber and grid in the viewfinder of a microscope. These aided in the
process of keeping track of where we were in the sequence of counting. Counts
were recorded on paper. Equations were used to extrapolate the numbers of
neurons "counted" based on the thickness of the microtomed tissue slices and
the average size of cells in the region being counted. Walle Naute of MIT
developed the techniques that were widely used back then. (Geez- I don't feel
that old).
I remember in the aftermath of the development of the microprocessor (into
the 80's now), being very excited about the new automated, digital methods
for making cell counts. (These methods were based on similar principles, but
eliminated the possiblity of human error due to attentional fatigue that is
associated with such a monotonous task. We averaged 3 "counts" of the same
tissue slides to help reduce the effect of such inevitable sampling (human)
error. In addition, I recall that the results of at least 2 separate counters
were used.. . .talk about intrinsic motivation !) I had moved on to
different dependent variables at the time, and did not use the newer,
automated techniques myself. I would imagine that by now this technology has
ungone even further development.
Any more up-to-date anatomists out there ??
Hope this helps,
Sandra
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Sandra Nagel Randall, Ph.D.
Wayne County Community College District, MI
Department of Human and Community Development
Athabasca University, Alberta, Canada
Biopsychology Consultant
[EMAIL PROTECTED]
Off: 248-948-8162
Fax: 248-948-5090
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