Effect of Amisulpride on Hippocampal Neurogenesis in an Experimental Model of Stressed Rats

Abstract

Sulpiride a selective antagonist at dopamine D2 and D3 receptors. This action dominates in doses exceeding 600 mg daily. In doses of 600 to 1, 600 mg, sulpiride shows mild sedating and antipsychotic activity. Its antipsychotic potency compared with chlorpromazine is only 0.2 (1/5). In low doses (50 to 200 mg daily) its prominent feature is antagonism of presynaptic inhibitory dopamine receptors accounting for some antidepressant activity and a stimulating effect. Therefore, these doses were used as a second line antidepressant. Additionally, it alleviates vertigo. Amisulpride functions primarily as a D2 and D3 receptor antagonist. It has high affinity for these receptors with dissociation constants of 2.2 nM and 2.4 nM, respectively. Although standard doses used to treat psychosis inhibit dopaminergic neurotransmission, low doses preferentially block inhibitory pre-synaptic autoreceptors. This results in a facilitation of dopamine activity, and for this reason a low dose amisulpride is used to treat dysthymia. Amisulpride and its parentsulpiride have been shown to bind to and activate the GHB receptor at doses that are used for therapeutic purposes.Though it has long been widely assumed that dopaminergic modulation is solely responsible for the respective antidepressant and antipsychotic properties of amisulpride.It has recently been shown that it also acts as a potent antagonist at the 5-HT7 receptor (Maitre et al.,