The behavioural effects of 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) in mice

The evidence for the involvement of the 5-HT1A receptor in 5-HT syndrome induced in mice by tryptamine.

“…It has been suggested that head weaving is connected with the dopaminergic mechanisms and is blocked by dopamine receptor blockers and depletors in rats (13). In addition, we reported that head weaving induced by 8-OH-DPAT is selectively inhibited by haloperidol (7). The present results with haloperidol, taken together with the results of previous studies, further support that head weaving is linked with the dopaminergic neurons.…”

“…We also recently reported that the 5-HT1A receptor agonist 8-OH-DPAT induces the 5 HT syndrome in mice by the stimulation of 5 HT1A receptors (7). In the present study, we showed that the 5-HT syndrome induced in mice by tryptamine is due to the activation of the 5-HT,A receptor.…”

Effects of 8‐OHDPAT and 5‐HT1A antagonists WAY100135 and WAY100635, on guinea‐pig behaviour and dorsal raphe 5‐HT neurone firing

“…In a previous study the non-selective 5-HT1 antagonist, metergoline, blocked myoclonic behaviour whereas other antagonists such as methysergide and mianserin only had weak effects (Chadwick et al, 1978;Luscombe et al, 1981). In summary, there is evidence indicating involvement of postsynaptic 5-HTIA receptor activation in the 5-HT behavioural syndrome in rats, mice (Tricklebank et al, 1984;Dourish et al, 1985;Yamada et al, 1988), and guniea-pig while the present study clearly demonstrates that both WAY100135 and WAY100635, selective antagonists at the 5-HTIA receptor (Fletcher et al, 1993a, b) (Mundey et al, 1994b) (Fornal et al, 1989) and (S)-UH-301 (Arborelius & Svensson, 1992) and (-)-tertatolol (Jolas et al, 1993) can also increase DR neuronal firing in the cat and rat.…”

“…Histological analysis revealed that all units recorded which were inhibited by 8-OHDPAT were located within the midline of the guinea-pig DRN. 8-OHDPAT produced a dose-related inhibition of the slow firing neurones in the guinea-pig DRN ( Figure (Tricklebank et al, 1984;Dourish et al, 1985;Yamada et al, 1988). The role of other 5-HT receptor subtypes with which 8-OHDPAT has affinity (e.g.…”

“…Presynaptic 5-HT depletion does not affect the 8-OHDPAT-induced syndrome in either rats or mice (Dourish et al, 1985;Yamada et al, 1988) indicating that the elements of the 5-HT syndrome are mediated via postsynaptic An increase in 5-HT synthesis and hence 5-HT levels (Hess & Doepfner, 1961;Grahame-Smith 1971a;Ortmann et al, 1980) also elicits the syndrome, as do the direct agonists 5-methoxy-N,N-dimethyltryptamine (Grahame-Smith 1971b;Green et al, 1981), 5-methoxytryptamine (Green et al, 1976), (+ )-lysergic acid diethylamide (LSD) (Trulson & Jacobs, 1976a) and quipazine (Green et al, 1976;. Furthermore 5-HT releasers such as fenfluramine and p-chloroamphetamine (Trulson & Jacobs, 1976b;Deakin & Green, 1978) also cause elements of the 5-HT syndrome.…”