Evoked auditory activity within the telencephalon of the bullfrog (Rana catesbeiana)

Two auditory responsive regions in the telencephalon of the bullfrog were localized by combining systematic evoked potential depth recordings with subsequent histological studies. Large negative potentials (n1) from the ventral striatum and large positive potentials (p1) from the medial pallium were recorded in response to complex sounds with parameters similar to those found in the species-specific vocalizations. Simple acoustic stimuli, such as clicks and single tones, failed to excite these regions. Although the source of the auditory afferents to the medial pallium is presently uncertain, based on our electrophysiological recordings and previous anatomical studies it seems likely that the ventral striatum is the next ascending area above the auditory thalamus in the anuran auditory pathway.