Involvement of 5-HT receptor subtypes in the discriminative stimulus properties of mescaline.
In order to further evaluate the extent to which particular 5-HT receptor subtypes (5-HT1, 5-HT2) might be involved in the behavioral effects of hallucinogenic drugs, rats were trained to discriminate mescaline (10 mg/kg i.p.) from saline and were given substitution (generalization) and combination (antagonism) tests with putatively selective serotonergic and related neuroactive compounds. The mescaline cue generalized to relatively high doses of the 5-HT2 agonists, 2,5-dimethoxy-4-methylamphetamine (DOM), LSD and psilocybin; the extent of generalization to 5-HT1 agonists (8-hydroxy-2-[diethylamino]tetralin (8-OHDPAT), RU-24969 and 8-hydroxy-2-[di-n-propylamino]tetralin (TFMPP] was unclear. Combinations of the training drug and sufficiently high doses of 5-HT2 antagonists (ketanserin, LY-53857, pirenperone) were followed by saline-lever responding; less selective central 5-HT (metergoline), and DA (SCH-23390, haloperidol) antagonists, did not block the mescaline cue. These data suggest that 5-HT2 receptors are involved in the stimulus properties of mescaline.
Appel
J B
JB
Department of Psychology, University of South Carolina, Columbia 29208.
Callahan
P M
PM
D000818:Animals; D004193:Discrimination Learning / Q000187:drug effects; D004192:Discrimination, Psychological / Q000187:drug effects*; D018492:Dopamine Antagonists; D008297:Male; D008635:Mescaline / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology
D018492:Dopamine Antagonists; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D008635:Mescaline