title: Behavioral effects of lithium on presynaptic sites of catecholaminergic neurons in the mouse.
abstract: The effect of lithium on locomotor activity in mice was studied and an attempt was made to elucidate the neuronal mechanisms involved. Lithium chloride (200 mg/kg, i.p.) administered acutely or daily for 7 days did not affect locomotor activity. A single injection of apomorphine at a low dose of 0.25 mg/kg (i.p.) markedly decreased locomotor activity but repeated injection of the drug produced hyperlocomotion accompanied by sniffing. Methamphetamine (1 mg/kg, i.p.), haloperidol (0.02 mg/kg, i.p.), thyrotropin releasing hormone (5 mg/kg, i.p.) or apomorphine (1 mg/kg, i.p.) exerted a biphasic action in locomotor activity, i.e. an initial increase and subsequent decrease. This initial hyperlocomotion induced by these drugs, except for apomorphine, was inhibited by lithium (200 mg/kg, i.p. X 1) or a low dose of apomorphine (0.25 mg/kg, i.p. X 1). The subsequent hypolocomotion was also attenuated by lithium, but not by apomorphine. Imipramine (10 mg/kg, i.p.) increased the hyperlocomotion induced by methamphetamine. The inhibitory effect of tetrabenazine (5 mg/kg, i.p.) on locomotor activity was attenuated after repeated treatment with lithium (200 mg/kg, i.p. X 7) or imipramine (10 mg/kg, i.p. X 7). The results suggest that lithium may inhibit dopaminergic neuron activities, probably not through an activation of presynaptic dopamine autoreceptors.
mesh_terms: D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D002395:Catecholamines / Q000502:physiology*; D004347:Drug Interactions; D006220:Haloperidol / Q000494:pharmacology; D008094:Lithium / Q000494:pharmacology*; D008297:Male; D008694:Methamphetamine / Q000494:pharmacology; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D009474:Neurons / Q000502:physiology*; D013569:Synapses / Q000187:drug effects*; D013747:Tetrabenazine / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology
chemical_list: D002395:Catecholamines; D008694:Methamphetamine; D013973:Thyrotropin-Releasing Hormone; D008094:Lithium; D006220:Haloperidol; D001058:Apomorphine; D013747:Tetrabenazine