Substantia nigra dopaminergic unit activity in behaving cats: Effect of arousal on spontaneous discharge and sensory evoked activity

摘要: Single-unit activity of dopaminergic neurons in the substantia nigra was recorded freely moving cats during a variety conditions designed to shed light on hypotheses that these are involved regulation arousal-stress and/or selective attention. Both aversive and non-aversive arousing experimental were used, including tail pinch, immersion feet ice-water, white noise, inaccessible food, feeding, grooming, rats, somatosensory stimulation. None had an effect tonic neuronal discharge rate. However, did exhibit brief excitatory inhibitory responses phasic auditory or visual stimuli presented when cat sitting quietly. These dramatically attenuated if aforementioned behavioral arousal. This sharply contrasts with inability same influence spontaneous The sensitivity this sensory response concurrent condition supports hypothesis attentional processes responding. lack responsiveness arousal/stress manipulations play permissive, rather than active, role processes.