IN-VIVO LI-7 NMR DIFFUSION STUDIES IN RAT-BRAIN

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.