5ht Involvement in Tryptamine Induced Behaviour in Mice

Abstract

Several studies have shown that tryptamine (T) administered to rodents pretreated with an MAO inhibitor produces characteristic behaviour (e.g. Clineschmidt and Lotti 1974, Marsden and Curzon 1978, Luscombe et al 1982). Depletion of 5HT decreases this response indicating involvement of neuronal 5HT (Foldes and Costa 1975, Marsden and Curzon 1978). Other studies however have suggested T may act directly on 5HT receptors while another possibility is the existence of specific T receptors in brain (Kellar and Cascio 1982). Recent behavioural studies have supported the concept of distinct 5HT and T receptors; for example T infused into rat hypothalamus causes hyperthermia while 5HT produces hypothermia (Cox et al 1981). Alternatively T could modulate 5HT mediated transmission via an action at 5HT receptors (Jones and Boulton 1980). The present study investigated the behavioural effects of administered T in the mouse with a view to elucidating the role of endogenous 5HT and 5HT receptors in the response.