Tonic immobility and the serotonergic system in chickens: differential blockade of receptors by cyproheptadine and cinanserin.
Low doses of serotonin potentiated immobility durations in 2 1/2-week-old chickens (Gallus gallus) while high doses attenuated the response. Cyproheptadine, a serotonergic antagonist, eliminated increases generated by low doses of serotonin and reduced durations in control subjects, but had no effect on the attenuation produced by high doses of the drug. Cinanserin, another serotonergic blocker, also eliminated the potentiation generated by low doses of serotonin and partially reduced the attenuation caused by high doses, but had no effect on immobility durations in control animals. Larger doses of cinanserin eliminated the attenuation produced by high doses of serotonin and increased durations in control subjects. Results are discussed in terms of the differential blockade of various serotonin receptors.
Hennig
C W
CW
Psychology Department, Salem College, WV 26426.
Steinhoff
W C
WC
Braughler
S A
SA
D000818:Animals; D001921:Brain / Q000187:drug effects*; D002645:Chickens; D002928:Cinanserin / Q000494:pharmacology*; D002934:Cinnamates / Q000494:pharmacology*; D003533:Cyproheptadine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D009043:Motor Activity / Q000187:drug effects*; D011985:Receptors, Serotonin / Q000187:drug effects*; D012701:Serotonin / Q000494:pharmacology
D002934:Cinnamates; D011985:Receptors, Serotonin; D003533:Cyproheptadine; D012701:Serotonin; D002928:Cinanserin