Brain myo-inositol level is elevated in Ts65Dn mouse and reduced after lithium treatment

The segmental trisomy Ts65Dn mouse is a novel model of Down syndrome (DS). The purpose of this study was to measure brain levels of myo-inositol (mI), N-acetylaspartate (NAA), and other metabolites in Ts65Dn mice using in viv o H-1 magnetic resonance spectroscopy (MRS), and to determine whether lithi um (Li) treatment alters brain mI level. The ratio of mi over total creatin e (Cr), ml/Cr, was significantly elevated (mean change +38%), while NAA/Cr was significantly decreased (mean change -18%) in Ts65Dn mice (n = 5) compa red with control mice (n = 7). This is consistent with H-1 MRS findings in DS human adults. Brain ml/Cr of the entire sample group (n = 12) was reduce d (mean change -15%) following Li treatment, supporting the Li-induced ml d epletion hypothesis. NeuroReport 11:445-448 (C) 2000 Lippincott Williams & Wilkins.