Tonic immobility in domestic fowl: possible interaction of serotonergic and dopaminergic mechanisms.
Treatment with the dopamine (DA) receptor blocker, haloperidol, enhanced tonic immobility (TI) duration. Fenfluramine, a receptor agonist for serotonin (5-HT), reversed this effect. Tryptophan produced long TI reactions, and is believed to do so due to impaired synaptic transmission of 5-HT following its direct inhibitory effects on 5-HT neurons. DA receptor stimulation by apomorphine prevented the tryptophan potentiation of tonic immobility. The results suggest that serotonergic and dopaminergic systems may interact with respect to tonic immobility.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D002375:Catalepsy / Q000378:metabolism; D002645:Chickens; D005277:Fenfluramine / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology; D006801:Humans; D007103:Immobilization / Q000187:drug effects*; D011954:Receptors, Dopamine / Q000187:drug effects / Q000378:metabolism*; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D014364:Tryptophan / Q000494:pharmacology
D011954:Receptors, Dopamine; D011985:Receptors, Serotonin; D005277:Fenfluramine; D014364:Tryptophan; D006220:Haloperidol; D001058:Apomorphine