Involvement of the sensory cortex in adrenocortical responses following photic and acoustic stimulation in the rat

In order to examine the possibility that the sensory cortex participates in the mediation of adrenocortical responses following sensory stimuli, the effects of photic and acoustic stimuli on plasma corticosterone were studied in rats with either visual or auditory cortex ablation. In animals with visual cortex ablation, the adrenocortical response to acoustic stimuli was intact; however, it was significantly reduced following photic stimulation. On the other hand, in animals with auditory cortex ablation, the response to acoustic stimulation was significantly reduced, but the response to photic stimulation remained intact. These data demonstrate the participation of the specific sensory cortex in adrenocortical responses following the stimulation of the corresponding sensory modality. The possible mechanisms involved may be either a tonic facilitatory effect of the specific cortex on subcortical mechanisms or the transmission of the specific stimuli in the primary sensory pathways, to achieve a full adrenocortical discharge.