Pimozide mitigates excessive running in the activity-stress paradigm.
The present study investigated the role of dopamine in the maintenance of behaviors observed in the activity-stress paradigm. In Experiment 1, several doses (0, 0.125, 0.25, 0.50, and 1.0 mg/kg) of the dopamine D2-receptor blocker, pimozide, were administered to rats maintained on an ad lib feeding schedule. Results indicated that 0.25 mg/kg pimozide did not disrupt running activity when compared to control animals. In Experiment 2, injections of either 0, 0.25, or 0.50 mg/kg pimozide were given every 12 hours to rats subjected to the activity-stress paradigm. Although 0.25 mg/kg pimozide had no effect on dark-phase activity, it significantly suppressed light-phase activity and subsequently increased the number of survivors in the paradigm. It was concluded that dopamine plays a role in maintaining high running levels in the activity-stress paradigm.
Lambert
K G
KG
Department of Psychology, Randolph-Macon College, Ashland, VA 23005.
Porter
J H
JH
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D008027:Light; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D010868:Pimozide / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013276:Stomach Ulcer / Q000139:chemically induced / Q000503:physiopathology; D013315:Stress, Psychological / Q000523:psychology*
D010868:Pimozide