SLOW POTENTIALS AND SPIKE ACTIVITY OF RETINA

Abstract

In the carp''s inverted retina the relation between slow potentials and spike discharge in response to photic stimulation was studied. On illumination of a small area of the retina, positive slow potentials were produced within and very closely around the illuminated area, while negative ones were recorded from the surrounding areas. In units with contrast organization the discharge type changed from "on" to "off" or from "off" to "on", when a spot of test light was moved from the center to the periphery of the r ec eptive field and the slow potentials changed from positive to negative as well. The extent of the receptive field of a unit was of the same order as that of the slow potential field. Effects of the size of a stimulus area resulted in variation in shape of the slow potentials from simple positive form to positive-negative complex and in association with this the rate of discharge of units with contrast organization decreased.