Responses of caudate nucleus neurons to acoustic stimulation during functional blockade of the centrum medianum of the thalamus in the cat

Responses of caudate nucleus to sound clicks (0.5/s) were recorded extracellularly in chronic experiments on cats under conditions of functional blockade of centrum medianum. Analysis of average poststimulus histograms has shown that functional blockade of centrum medianum in 30% of the caudate nucleus neurons induced a decrease in phasic activating responses to sound signals and in 52% of neurons their disappearance. A decrease in the level of spontaneous caudate nucleus neurons activity was also found. Direct pathways from centrum medianum to caudate nucleus are discussed for their significance in transmission of sound signals to caudate nucleus neurons.