[The retinotopic organization of the posterior suprasylvian area of the cerebral cortex in the cat].

Posterior suprasylvian area (PSA) is one of the extrastriate visual structures of the cat cortex. Representation of the visual field in the PSA has been investigated by the mapping method. Results of experiments revealed that receptive fields (RF) of the PSA neurons were located mostly in the upper contralateral quadrant of the visual field.

[Structure of receptive fields of visually sensitive neurons of the cat hippocampus].

Structure of receptive fields of visually sensitive neurons in areas CA1 and CA3 of the dorsal hippocampus was investigated in alert cats with the brain-stem pretrigeminal section. The receptive field (RF) structure of 76 hippocampal neurons was analyzed by methods of scanning the RF by moving stimuli and mapping all their surface by a stationary flashing spot. According to presented data the neurons were classified into three groups: neurons with homogeneous structure of the RF (54%), with nonhomogeneous (28%) and neurons more sensitive to stimulus motion (18%) than to a stationary flashing light.

[Inhibitory components in responses of neurons of the lateral suprasylvian area of the cat cortex].

Inhibitory components of neuronal responses to moving visual stimuli in the lateral suprasylvian area of the cat cortex have been studied. Comparison of PST histograms of responses to two opposite directions of the movement allows revealing changes in the spatial localization of discharge centres in receptive fields relative to the movement direction. In all neurons investigated which revealed monotonous stationary structure of receptive fields no subregions coincidental with the inhibitory components of the responses are found.

[Responses of neurons of dorsal hippocampus field CA1 to visual stimulation in the cat].

In acute experiments on cats with pretrigeminal brain-stem section responses of 46 hippocampal neurons were investigated. Most neurons (71%) had small sizes of visual receptive fields. The responses of neurons to stationary stimuli were of phasic (66%), as well as tonic (34%) types.

[Organization of the substructure of the receptive fields of neurons of the lateral suprasylvian area of the cat cortex].

The substructure of receptive fields of the lateral suprasylvian area neurons was investigated in cats. It was shown that the majority of receptive fields investigated were organized of subelements with different qualitative characteristics according to their responses to moving visual stimuli. With the unmasking method of stimulation, small amplitudes of the motion evoked, as a rule, directional responses, whereas with the masking method the same amplitude of the motion produced nondirectional responses.