Feather position of the pigeon after intrahypothalamic injections of noradrenaline, 5-hydroxytryptamine and carbachol

Summary A slowly increasing ptiloerection was seen after the intrahypothalamic injections of NA; 5-HT was followed by preening and subsequent rapid feather fluffing, and carbachol produced an immediate sleeking of feathers. The naturally occurring complementary relationship between shivering thermogenesis and ptilomotion diminished or disappeared after the drugs, but feather position seemed to remain well related to the arousal state of the pigeon.Acknowledgment. This work was supported by the Emil Aaltonen Foundation.