optic nerve info. wanted
abotelho at mpcnet.com.br
Wed Jun 17 02:32:30 EST 1998
I suggest you begin with Kandel E, Schwartz R "Principles of Neuroscience"
3rd ed. (or would it be Neural Sciences?).
You want to know exactly HOW the visual information is transduced (from
light to cell potentials) at the retina and how this information is encoded
and transmitted through the optic nerve to the cerebral cortex. It's a
rather complex system, but I think most, if not all, information coming from
the retina is in the form of "frequency of action potentials" along the
nerve's neurons. The passage from light to those action potentials is
something really complex.
Besides the interactions (of the ganglion cells) responsible by the
receptive fields (including inhibitory activity from specialized cells),
there are cells more sensitive to some light wavelength, and other cells
more sensitive to other.
The entire system is so complex that we study its basic properties, but few
people test joining all the properties to assemble (computer) models and
verify whether we know all the necessary properties for it to work or not.
Richard Norman escreveu na mensagem
<6m3jhl$9j6$1 at denws03.mw.mediaone.net>...
>In article <6m3f3i$jtp$1 at nnrp1.dejanews.com>, aquila1 at hotmail.com says...
>>I am working on a little project and need to know information / sources of
>>information regarding any work done on mapping the axons of the human
>>nerve. Specifically, I need to know everything that happens after an
>>processed by the retina. I.e., is a certain color and frequency and
>>location assigned to each specific axon ? Any help you can give me is
>>appreciated. Please don't respond at too technical a level as I am not a
>>neuroscientist but an amateur.
>>samuel.mason at ericsson.com
>There is an awful lot of stuff on optic nerve fibers, but I am not sure
>how much specifically on humans. If you don't wan't too technical an
>answer, your best bet is first to sit in a good library and browse whatever
>they have on introductory neurobiology or vision. Also physiology texts
>also have sections on sensory information processing and vision.
>Depending on how much background you need, you might even start with a
>good college level intro biology text to give you the background to read
>It is hard to know exactly what you want from your question. You ask
>about "everything that happens after an image is processed by the retina".
>That means, everything in the CNS, mostly visual cortex, and that means
>a lot, indeed. On the other hand, you ask about axons in the optic nerve,
>and that means "everything that happens inside the retina". That is,
>the information sent to the brain in the optic nerve depends on the
>circuits in the retina itself, not in the CNS.
>Your question about "frequency" suggests that the search for data is
>somewhat confused with the auditory system. Watch out! Getting involved
>in "spatial" frequency analysis is far more technical than you want!
>What you want is information on the "receptive field" properties of
>retinal ganglion cells.
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