Superior colliculus cell responses to to electrical stimulation of the retina

Superior colliculus cell discharges in response to electrical stimulation of the retina were investigated in rabbit. In contrast with the responses at the optic tract level both polarities evoked discharges of equal latencies suggesting a convergence of ON- and OFF-centre retinal ganglion cells upon one collicular unit. Three typical patterns of responses could be distinguished. Thus, 40% of cells reacted with a burst, 47% with a prolonged discharge, and 5% responded by a transient inhibition. The responses of the remaining cells could not be classified.