Unit recordings from a new auditory area in the frontal neostriatum of the awake starling (Sturnus vulgaris).

Auditory units were recorded from a restricted region of the frontal neostriatum of the awake starling. This area (Field GA) was located latero-dorsal from the nucleus basalis and more closely associated with the caudal regions of the thalamo-frontal tract. Most units (46%) showed on-excitation to pure tones and white noise stimuli. No well-defined sustained firing was seen, but 15% of the units showed a weak type of excitation which outlasted the stimulus (long-lasting response). Tuning curves were broad. Unit response ranges extended from 150 Hz to 7.0 kHz (at 70--80 dB SPL). Habituation to repeated stimuli was obvious and also lability of response pattern; 26% of auditory units would not be reliably classified using pure tones or white noise. It is suggested that the response properties of Field GA units are typical of sensory integration areas, although the source of input is unknown at present.