Neurophysiological studies of sensory gating in rats: effects of amphetamine, phencyclidine, and haloperidol.
Central mechanisms of sensory gating were assessed in Sprague-Dawley rats by an evoked potential technique similar to one that we have previously used to show diminished sensory gating in psychotic patients. Middle latency (15-50 msec) auditory evoked potential responses were recorded at the skull in unanesthetized freely moving animals. Gating mechanisms were assessed in a conditioning-testing paradigm by measuring the suppression of response to a 74 dB click test stimulus following an earlier identical conditioning stimulus at 0.5-sec intervals. The rats demonstrated significant suppression of the N50 response to the second auditory stimulus. Amphetamine treatment significantly interfered with the suppression of the response to the second stimulus; haloperidol, injected after the amphetamine, returned the conditioning-testing ratio toward normal values. Phencyclidine caused a similar decrease in suppression and was similarly antagonized by haloperidol. During some periods of hyperarousal, animals showed spontaneous loss of suppression; this condition could be reversed by haloperidol treatment. These results with psychotomimetic drugs in an animal model parallel abnormalities in sensory gating previously observed in psychotic human subjects.
D000818:Animals; D001306:Auditory Pathways / Q000187:drug effects; D001307:Auditory Perception / Q000187:drug effects*; D001921:Brain / Q000187:drug effects*; D003213:Conditioning, Psychological / Q000187:drug effects; D003913:Dextroamphetamine / Q000494:pharmacology*; D004347:Drug Interactions; D005072:Evoked Potentials, Auditory / Q000187:drug effects; D006220:Haloperidol / Q000494:pharmacology*; D008297:Male; D010622:Phencyclidine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D010622:Phencyclidine; D006220:Haloperidol; D003913:Dextroamphetamine