An investigation of amphetamine-induced release of 5-HT from rat hippocampal slices

The spontaneous release of [3H]5-HT from hippocampal slices, preincubated with [3H]5-HT, was increased by dopamine (P less than 0.001) and d-amphetamine (P less than 0.001) in a dose-dependent way. d-Amphetamine (10(-5) M) also increased (P less than 0.05) the release evoked by KCl (26 mM) whereas dopamine did not. The effects of dopamine and d-amphetamine on spontaneous [3H]5-HT release were antagonised by haloperidol and cis-flupenthixol. The release of [3H]HT evoked by KCl (26 mM) was reduced by noradrenaline (P less than 0.001) for conc. of 10(-5) M. It is concluded that the effects of d-amphetamine on [3H]5-HT release are probably mediated, in part by presynaptic dopamine receptors located on the 5-HT nerve terminals and that this response may depend upon the release of dopamine from adjacent terminals.