The injection of lithium chloride into lateral ventricule of the brain (LV) or subarchnoid space of rats via chronically implanted cannula resulted in significantly analgesic effect that could be reversed by naloxone or phentolamine

but not by propranolol

lysergic acid diethylamine (LSD)and bicuculline.Rats were sacrificed by decapitation half an hr. after injection of Licl into LV for the determination of the content of norepinephrine (NE) in the brain. It was found that the content of NE of forebrain and diencephalon decreased by 17-27%

and 26-29% respectively.This result suggests that the analgesic effect of Li takes place in the central nervous system and it may be associated with the change of metabolism on enkaphalin and NE that produced analgesic effect via opiate receptors and alpha-adrenoceptors respectively