[Functional characteristics of visual cortex neurons in the squirrel]

The main functional classes of neurons in the squirrel visual cortex are described. The following classes were revealed on the basis of the receptive field organization and the pattern of response to visual stimuli: direction-non-selective neurons (14%), direction-selective neurons (30%), orientation-selective neurons (49%); 7% of neurons were unclassified. Direction-selective neurons and some non-selective ones were specifically sensitive to high speed of the stimulus movement (hundreds deg/s). Orientation-selective neurons differed in the degree of on- and off-zones overlapping; they may include analogues of simple and complex neurons.