Estimation of local kinetic parameters of exchange of lithium in various substructures of the mouse brain, using the 6Li(n, alpha)3H-nuclear reaction.

The time-constant of lithium (Li)-clearance from the plasma was of the order of 2 hr, while the mean time-constant of lithium-clearance from the bulk of the body cells into the plasma was about 10 times this value. The mean time-constant of lithium ion (Li+)-clearance from various brain substructures (corpus callosum, striatum, hippocampus, neocortex) was comparable to the latter (15-25 hr). Comparison of samples where either a slight diffusion or no diffusion at all had occurred, suggest that between the nerve bodies and the trunks, lithium ions are not uniformly distributed.