Gary Jasdzewski wrote:
>> When writers say that the cortex is only 6 layers deep, do they mean it's
> simply 6 neurons deep or 6 layers that are thicker than 1 neuron?
Each layer is composed of more than one neuron in thickness. The
rat has a cortex about 1.8mm thick. As neuron somas (bodies) are
about 10 to 20 micrometres in diameter, you can see that there
are many neurons "above each other" in each layer. There are
layers only one cell thick - the Purkinje cell layer in
cerebellum springs to mind, but this is not the norm. The number
of layers, and the extent to which they are sub-divided varies
across cortex (and authors ;-)
--
Dr Richard Vickery
School of Physiology & Pharmacology, UNSW, Australia, 2052
ph. 61 2 93851676, fax 61 2 93851059
http://www.med.unsw.edu.au/Physiology/School/staff/vickery/Welcome.html
