A radiotracer technique in combination with lithium injection was used to probe the effects of acute and chronic ethanol administration on poly-phosphoinositide turnover in mouse brain. C57Bl/6J mice were injected intracerebrally with 3H-inositol to label the inositol phospholipids and inositol phosphates in brain. Subsequently, the accumulation of labeled inositol monophosphates was assessed 4 hr after i.p. injection of lithium (6 meq/kg body wt). Using this experimental paradigm, results indicated a significant increase in labeled inositol monophosphates in the chronic ethanol group and a decrease in the same compound in animals after acute ethanol intoxication.