Effect of intracellular lithium on snail neurones

Abstract

IT is well established that lithium salts are effective in the treatment of manic depressive illness^1,2, but the way they act is little understood. Some time ago, as part of a study on the electrogenic sodium pump, it was noticed that high levels of intracellular Li⁺ or Na⁺ seemed to increase the potassium conductance of the snail nerve cell membrane^3,4. Because of the greatly increased interest in Li⁺ itself, we have now confirmed the original observations, and have shown that detectable effects occur at quite low levels of intracellular Li⁺. Such an increased membrane conductance to potassium would tend to decrease the membrane excitability and hence stabilise the cell. If a similar response to intracellular Li⁺ occurs in man, it could be the basis for its therapeutic effects.