Amphetamine sensitization: nonassociative and associative components.
Rats, pretreated with amphetamine (AMPH, 1 mg/kg) or saline for 2 weeks, were challenged with AMPH (0.5 mg/kg) or saline following 1 week of abstinence, and locomotion was measured. In Experiments 1 and 2, the pretreatment occurred in various contexts (home cage, novel box, test box). Sensitization was observed only when pretreatment context and test context were the same; a context switch abolished sensitization. When rats anesthetized with chloral hydrate were pretreated with AMPH, sensitization was completely dependent on the pretreatment, but independent of context. This "zero context" condition isolated the basal level of excitation attributable to unconditioned neural change to determine the role of contextual input to be a modulator that enhances or inhibits sensitization.
Wang
Ying-Chou
YC
Department of Psychology,Ching Kuo Institute of Management and Health, National Chung Cheng University, Chia Yi 621, Taiwan. ycwang@ems.cku.edu.tw
Hsiao
Sigmund
S
D000661:Amphetamine / Q000494:pharmacology*; D000818:Animals; D001245:Association Learning / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
D000661:Amphetamine