[Effect of cat motor cortex on the formation of lateral geniculate nucleus responses evoked by contralateral superior colliculus stimulation].

Abstract

It was shown in experiments on anesthetized cats that motor cortex (MC) stimulated by single current pulse caused formation of the lateral geniculate nucleus (LGN) response. It was established that changes in formation of LGN response evoked by contralateral superior colliculus (SC) stimulation were observed by condition of the precedence of LGN response evoked by stimulation of the MC. The expressiveness level of that decrease depended on intervals between conditioning cortical and testing tectal stimuli. At the same time the stimulation of the MC by single current pulse caused no changes in formation of the visual evoked potential of LGN. However, a significant decrease of the visual response of that part of the SC which stimulation caused formation of the LGN response was observed under the same conditions. The obtained data permit supposing that MC checks realization of the tectal influences on the LGN function on the tectal level. It is assumed that realization of the effect of the saccadic suppression of the LGN function in which accomplishment, as it was supposed earlier, the SC took part, was controlled by the MC phasic influence.