[Functional characteristics of the orientation-selective neurons in the frontal visual field of the striate cortex in the baronduki].

The extracellular activity of 150 neurons (field 17) from binocular region of the visual cortex in the Siberian chipmunk was investigated. 65% of neurons proved to be selective to orientation and selective (but differently) to the direction of movements of the contrast boundaries and light. 18% of neurons were nonselective to the orientation and direction of the stimulus movement. 17% of neurons were activated only with the total illumination of the receptive field. Out of 39 orientation-selective neurons investigated by the moving and stationary stimuli 16 neurons reacted only to the moving stimuli: 13 neurons responded to exposure to stationary bars with prolonged tonic activation, 7 neurons showed a short phasic response and 3 neurons--a phasically-tonic response. All the phasic neurons were a maximally activated at higher movement velocities compared with the tonic neurons. The possible analogy between fast-phasic and slow-tonic neurons and Y- and X-systems is discussed.