Effects of amphetamine on schedule-induced polydipsia.
A series of experiments examined the effects of amphetamine (AMPH) at various doses administration for different length of time on a schedule-induced polydipsia (SIP) and possible associations with behavioral activation. Two stages of a two-week AMPH treatment were introduced with interposed interval of two months. In terms of behavioral activation, AMPH induced a robust depression across stages but with less potency in the second one. As for the SIP performance, the effects manifested qualitative difference in the two stages. For the first stage, there were no differential effects of AMPH on stereotypy intensity during the facultative phase of the inter-rewarding interval. However, AMPH reduced the high frequency of licks in the adjunctive (schedule-induced) phase and increased the low frequency of nose pokes in the terminal (schedule-dependent) phase. In the second stage, AMPH had no effect on the frequency of licking whereas the efficiency of licking and the frequency of nose pokes were reduced. These results were interpreted to support the current viewpoint that the behavior of SIP displaying is relevant to the function of central dopaminergic systems. The results were further discussed in the considerations of behavioral competition, stress coping strategy, and also the impact of AMPH at different time.
Department of Drug Addiction, Armed Forces Beitou Hospital, Taiwan, ROC.
Yia-Ping
YP
Liu
Hung-Chin
HC
Wang
Ching-Jiunn
CJ
Tseng
Hung-Shan
HS
Tang
Tsai-Hsin
TH
Yin
Che-Se
CS
Tung
D000818:Animals; D003213:Conditioning, Psychological; D003913:Dextroamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D004327:Drinking Behavior / Q000187:drug effects*; D004334:Drug Administration Schedule / Q000662:veterinary; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013239:Stereotyped Behavior / Q000187:drug effects
D003913:Dextroamphetamine