Conditioning and experiential factors affecting the development of sensitization to apomorphine.
In 3 experiments, the role of conditioning and experiential factors in producing behavioral sensitization to apomorphine (APO) was examined. In each experiment, male rats received intermittent injections of APO (5.0 mg/kg s.c.) or vehicle (VEH) and were tested for locomotor activity in photocell arenas. Activity test experience was paired or unpaired with drug exposure or not given. After the pretreatment phase in each experiment, all rats were tested for activity after an APO injection. The results indicated that behavioral sensitization to APO develops with repeated treatments in the absence of drug-associated contextual environmental stimuli. The magnitude of the sensitization effect observed, however, was always greater in rats for which specific environmental cues were reliably associated with drug exposure. These findings indicate that behavioral sensitization to APO develops through both associational and non-associational mechanisms.
Mattingly
B A
BA
Department of Psychology, Morehead State University, Kentucky 40351-1689.
Gotsick
J E
JE
D000374:Aggression / Q000187:drug effects; D000818:Animals; D001058:Apomorphine / Q000494:pharmacology*; D001143:Arousal / Q000187:drug effects*; D001921:Brain / Q000187:drug effects*; D003213:Conditioning, Psychological / Q000187:drug effects*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D012931:Social Environment
D011954:Receptors, Dopamine; D001058:Apomorphine