Structural and Functional Characteristics of Hedgehog Polysensory Cortical Zone

Abstract

The study of the neuronal organization of the hedgehog associative cortical zone revealed that besides primitive characteristics this area possesses a number of progressive features. An electrophysiological approach revealed a great number of polysensory neurons. The method, based on the HRP retrograde axonal transport, enabled us to discover the connections between primitive associative LP and MD thalamic nuclei and the associative cortex. Motor conditioned reflexes connected with visual discrimination as well as reflexes to signals of different modalities were elaborated quite easily. Conditioning to a simultaneous visual-auditory complex was found impossible in hedgehogs. Bilateral ablation of associative area results in disruption of the fine components of sensorimotor integration. It is likely that a primitively organized associative system in hedgehogs participates in the formation of sensorimotor synthesis, but fails to realize complex acts of intersensory integration.