Alteration of escape from rewarding electrical brain stimulation by D-amphetamine.
Rats were trained both to barpress for and escape from locus coeruleus, midbrain periaqueductal gray and hypothalamic stimulation. Rate-intensity functions for intracranial self-stimulation (ICSS) behavior and latency-intensity functions for escape behavior were obtained for each electrode site in each animal. Following baseline, d-amphetamine was administered and responding was compared with the saline condition for both rate-intensity and latency-intensity functions. ICSS response rates were enhanced by d-amphetamine at all loci, particularly at threshold intensities, while escape responding was biphasically affected by d-amphetamine at all loci. D-amphetamine increased escape latencies at intensities which, under saline, elicited short escape latencies, while decreasing escape latencies at intensities which, under saline, elicited long escape latencies. A significant correspondence was noted between intensities which, under the influence of d-amphetamine, both elicited longer escape latencies and higher ICSS response rates, suggesting that in both ICSS and escape paradigms, animals were titrating the duration of the stimulus train. No site-specific effects of d-amphetamine upon escape behavior were noted.
D000818:Animals; D001921:Brain / Q000187:drug effects*; D001931:Brain Mapping; D002535:Cerebral Aqueduct / Q000187:drug effects / Q000502:physiology; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology; D003913:Dextroamphetamine / Q000494:pharmacology*; D004924:Escape Reaction / Q000187:drug effects*; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology; D008297:Male; D008636:Mesencephalon / Q000187:drug effects / Q000502:physiology; D051381:Rats; D012653:Self Stimulation / Q000187:drug effects*
D003913:Dextroamphetamine