title: Dopamine receptors mediating yawning: are they autoreceptors?
abstract: Yawning was induced in rats by the (+) enantiomer of 3PPP, while (-)-3PPP was inactive. Yawning was present 24, but not 1, 6 and 12 h after reserpine treatment. The (+)-3PPP-induced yawning was antagonized by haloperidol and sulpiride but not by domperidone. Reserpine-induced yawning was antagonized by sulpiride and by alpha-methyltyrosine suggesting that this behavior may be induced by endogenously released dopamine. Reserpine-pretreatment potentiated (+)-3PPP-induced yawning. The results argue against the view that yawning is the behavioural correlate of autoreceptor-mediated inhibition of DA transmission, and suggest that this behaviour is due to the stimulation of a special population of central postsynaptic DA receptors.
mesh_terms: D000818:Animals; D004294:Domperidone / Q000494:pharmacology; D004357:Drug Synergism; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D008781:Methyltyrosines / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000502:physiology*; D012018:Reflex / Q000502:physiology*; D012110:Reserpine / Q000494:pharmacology; D013237:Stereoisomerism; D013469:Sulpiride / Q000494:pharmacology
chemical_list: D008781:Methyltyrosines; D010880:Piperidines; D011954:Receptors, Dopamine; D004294:Domperidone; D013469:Sulpiride; D012110:Reserpine; C031476:alpha-methyl-m-tyrosine; C026539:preclamol; D006220:Haloperidol