Effects of lithium chloride on sleep patterns in the rat

Continuous EEG recordings were performed in rats both after saline injections (control days) and after LiCl treatments. LiCl administration was always followed by an initial period of general distress and sleep inhibition during 2 to 3 hr after low toxic doses (1.5 mEq/kg) and a much more longer period (10 hr) after high toxic doses (3 mEq/kg). Once this state was overcome, the pharmacological effect of lithimia seems to potentiate sleep and particularly paradoxical sleep (PS). It appears that this potentiation of PS occurs once lithimia reaches levels used in human therapeutics.