HELP : Need definition for the word

[Udin, Susan]

Dear JJ,
The word retinotopic refers to the organization of visual maps in the 
central nervous system.  For example, retinal ganglion 
cell axons terminate in particular locations in the tectum (superior 
colliculus); if you look at a row of retinal ganglion cells, say, extending 
from the nasal pole of the retina to the temporal pole, you'll find that 
there axon terminals line up in a row running from the back of the tectum to 
the front.  There also are retinotopic maps in areas that get retinal input 
indirectly.  For example, the primary visual cortex has a retinotopic map in 
which neighboring regions of the retina activate neighboring regions of the 
cortex.  

I hope this helps you.

Susan Udin
Department of Physiology
State University of New York
Buffalo, NY 14214
email: sudin at ubmedb.buffalo.edu