Structure of receptive fields of hyppocampal visually-sensitive neurons in the cat

Abstract

We studied the structure of receptive fields (RF) in the visually sensitive CA1 and CA3 fields of the dorsal hippocampus in alert cats subjected to pretrigeminal section of the brain stem. Scanning with moving stimuli and mapping the whole RF area with point by point application of a stationary stimulus, we studied 76 RF neurons. We found no significant differences in the response characteristics of neurons of fields CA1 and CA3. Our data are a basis for classifying the neurons in the following groups: homogeneous RF structure of the RF (54%) and nonhomogeneous structure (28%) and weak reaction to the standard stimulus, but a strong reaction to movement (18%). The results showed that responses of some of the hippocampal neurons exhibit high specificity. Thus, 9% of the neurons with nonhomogeneous RF structure disclosed with static stimuli reacted variously to a change in contrast and contours of moving stimuli. The data presented indicate that visually sensitive neurons of the hippocamus have a relatively well-developed mechanism for processing visual sensory information and this obviously ensures participation of the limbic system in visually controlled behavior of the animal.