Acute central effects of 5,6-dihydroxytryptamine in fowl
Nisticó, G.; Gargiulo, G.; Rotiroti, D.; Preziosi, P.
Archives Internationales de Pharmacodynamie et de Therapie 222(2): 267-271
1976
ISSN/ISBN: 0003-9780 PMID: 984979 Document Number: 104861
Infusion into the third cerebral ventricle of 5,6-dihydroxytryptamine (5,6-DHT) at doses of 50, 75 and 100 mu g in adult hens caused behavioural and electrocortical sedation and sleep after about 5-10 minutes. The sleep lasted 6-8 hours. Infusion of the drug also caused a monophasic or biphasic increase in body temperature for about 8 hours. Histochemical observations revealed a sustained decrease in yellow and green fluorescence in areas near the third ventricle, in the anterior hypothalamus and in the preoptic area, starting 21/2 hours after administration of 5,6-DHT. There were no significant changes in the fluorescence of the tegmental cell-bodies. It is suggested that the behavioural and electrocortical effects of 5,6-DHT are due to synergism with catecholamines released by the action of the drug; the hyperthermic effects are thought to be due to a more sustained release of 5-HT (5-hydroxytryptamine) and/or to a direct action on 5-HT receptors and/or inhibition of 5-HT re-uptake.