Lithium (Li) is widely used for the treatment of several psychiatric d
isorders and is the drug of choice in the treatment of bipolar disorde
rs. The mechanism of action of Li, however, is unknown. A knowledge of
brain Li concentration, its distribution in the brain, and its proper
ties in the cellular microenvironments may contribute significantly to
wards the understanding of its function. We recently demonstrated by i
n vivo Li-7 NMR the distribution and pharmacokinetics of Li ion in rat
brain. We have made diffusion measurements of Li in the head and brai
n regions of anesthetized rats using the localized STEAM (stimulated e
cho acquisition mode spectroscopy) technique suitably sensitized to di
ffusion. In this paper we demonstrate for the first time the feasibili
ty of Li diffusion measurements in the mammalian brain model with the
ultimate goal of performing such studies on humans under Li therapy.