title: The occurrence of tolerance to a central depressant effect of nicotine.
abstract: 1. Rats were injected with 0.8 mg nicotine/kg, 0.8 mg amphetamine/kg or with saline immediately before being tested for 30 min in activity boxes.2. During the first 3 trials the nicotine group were less active than the controls but from trial 5 onwards nicotine had a stimulant effect. The stimulant effect of the amphetamine did not alter with repeated injection.
mesh_terms: D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D003864:Depression, Chemical; D004361:Drug Tolerance; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009538:Nicotine / Q000494:pharmacology*; D051381:Rats
chemical_list: D009538:Nicotine; D000661:Amphetamine