In article <19991102224838.01262.00001421 at ng-xb1.news.cs.com> JoshCahoon,
joshcahoon at cs.com writes:
>Howdy. I'm taking an intro physiological psych class and I can't seem to get
>something straight. Is the cerebral cortex just the outer layer of the
>cerebrum? If you peel away the cerebral cortex, what cerebral structures are
>left. The limbic cortex, I guess...but any subcortical stuff?
Yep, that's pretty much right. The cerebral cortex is also called
"neocortex", meaning evolutionarily "new" material (don't know if that's
really a very good description, but it's a common one anyway. Underneath
that, you'll find "paleocortex", as in "old" cortex. This is stuff like
hippocampus and certain other limbic structures. I guess all this stuff
is refered to as "forebrain", and most of it has a laminar organization
of neurons. Below that you come to to "midbrain" and "hindbrain", which
are organized differently on the local level (i.e., instead of layers,
neurons are often organized into little lumps called nuclei, such as the
nucleus accumbens, the lateral geniculate nucleus, etc). Hopefully a real
anatomist is on hand in the group to correct any errors I'm making now.
>Oh, and while I'm asking questions, I wonder if any of you know what
>neurotransmitter the photoreceptors release (my text doesn't say).
Glutamate, mostly. In vertebrates, they release it all the time
("tonically"), and stop when you shine a light on them. In insects (and
possibly other invertebrates), they're off in the dark and release in the
light. Other cells in the retina, like some bipolar cells and amacrine
cells, release GABA too.