Effects of Lithium on Amino-acids in Mouse Brain in vivo

Abstract

LITHIUM exerts marked effects on the function of brain and peripheral nerve in vivo and in vitro and has been used successfully in the treatment of manic-depressive psychoses^1,2. Although the effects of lithium treatments on monoamine metabolism have been studied^3,4, the relationships which may exist between lithium injections and the content of free amino-acids of brain remain unexplored. Recently, it was shown that injection of lithium directly into the amygdala of monkeys which were awake exerts very potent and reproducible effects on the EEG. After these effects had subsided they could be re-induced by direct injections of L-glutamate into the same sites⁵. It was therefore postulated that glutamate exerts its pharmacological action in animals which were awake by increasing the permeability of CNS neurones to sodium or to lithium (the latter not normally being present)⁵. Our experiments were conducted to show whether lithium injections affect the content of glutamate in the brain.