Journal of Neurophysiology, Vol 43, Issue 3 832-850, Copyright © 1980 by APS
Spatial organizations of catfish retinal neurons. II. Circular stimulus
R. Y. Chan and K. Naka
1. Temporal dynamics of receptive-field components were identified by use
of circular stimuli whose diameter was modulated in white-noise fashion. 2.
A thin ring of light evoked a complex response from the horizontal-cell
soma but not from its axon. 3. All bipolar cells had a biphasic receptive
field whose incremental sensitivities were comparable for the field's
center and surround. 4. Type-N cells had a biphasic field whose two
components were segregated both in time and space. 5. Type-C cells showed
nonlinearities, which did not depend on the types of light inputs and which
were intrinsic to the cell. 6. Ganglion cells could be classified roughly
into two classes: small- and large-field cells. Their main nonlinearity was
rectification. 7. Our studies on the catfish retna have shown that the
distal cells are essentially linear in time and space and can be identified
functionally by any type of input. The proximal cells, however, have a
complex functional repertoire whose identification poses considerable
difficulty.
