[Cortico-subcortical interrelationships in the visual analyzer system at various stages of ontogenesis]

The influence of a corticofugal volley produced by single electrical stimulation of the visual projection cortical zone on the neuronal activity of LGB was studied in non-anaesthetized rabbits aged from three to thirty-five days. A coincidence was found between the time of appearance of nonspecific inhibitory corticofugal influences on the spontaneous activity of LGB neurons and the emergence of the first phasic-specific responses of the neurones of this level to a visual stimulus. It has been shown that the sensory flow at the LGB level can be controlled by non-specific inhibitory corticofugal influences at early periods of postnatal development. The appearance from the 15th day of life of specific responses to a corticofugal volley, including activation phases, leads to a greater complexity of the regulating Cortical influences on conduction of the afferent signal at the thalamic level. The data obtained are considered from the standpoint of integration of various levels of the visual analyser at different stages of ontogenesis.