[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 receptive fields of tonic and phasic neurons in cat pulvinar].

The receptive fields of 26% out of 163 pulvinar neurons were characterized by phasic pattern of responses whereas those of 15% of neurons had tonic characteristics. The receptive fields of 59% of neurons consisted both of tonic and phasic subfields. These findings suggested convergence of two types of afferents on the same pulvinar neuron.