Visual cortical neurons influenced by the oculomotor input: characterization of their receptive field properties.

A class of cells in cat visual cortex (area 17 and 18) had a tight correlation with spontaneous and electrically evoked PGO waves under reserpine. They tended to have high maintained activity and a large receptive field which was preferentially excited by fast moving slits. They were also direction selective and influenced through both eyes. For these cells, the selectivity for visual stimuli was dramatically altered in the presence of PGO waves induced by pontine stimulation. They were complex cells. A second class of cortical cells showed a moderate correlation with spontaneous PGO waves. Visually evoked activity of these cells was either excited or inhibited by evoked PGO waves in response to pontine stimulation. A third class of cells, the majority, did not seem to have any correlation with PGO waves. The second and third classes of cells could be either one of the 3 main categories of visual cortical cells, predominantly simple cells in area 17 and complex cells in area 18. The present study provided further support to a previous proposal that PGO waves in the visual cortex, as neural correlates of saccadic eye movements, modulate specifically the ongoing activity of a selective type of cortical cell. A type of complex cell in the deeper layers is supposed to integrate visual and oculomotor inputs. It is hypothesized that the consequence of oculomotor inputs to the visual cortex is specified by the type of cells which receive oculomotor inputs, rather than by the nature of the inputs themselves.