Lithium ameliorates altered glycogen synthase kinase-3 and behavior in a mouse model of fragile X syndrome

Biochem Pharmacol. 2010 Feb 15;79(4):632-46. doi: 10.1016/j.bcp.2009.09.023.


Fragile X syndrome (FXS), the most common form of inherited mental retardation and a genetic cause of autism, results from mutated fragile X mental retardation-1 (Fmr1). This study examined the effects on glycogen synthase kinase-3 (GSK3) of treatment with a metabotropic glutamate receptor (mGluR) antagonist, MPEP, and the GSK3 inhibitor, lithium, in C57Bl/6 Fmr1 knockout mice. Increased mGluR signaling may contribute to the pathology of FXS, and the mGluR5 antagonist MPEP increased inhibitory serine-phosphorylation of brain GSK3 selectively in Fmr1 knockout mice but not in wild-type mice. Inhibitory serine-phosphorylation of GSK3 was lower in Fmr1 knockout, than wild-type, mouse brain regions and was increased by acute or chronic lithium treatment, which also increased hippocampal brain-derived neurotrophic factor levels. Fmr1 knockout mice displayed alterations in open-field activity, elevated plus-maze, and passive avoidance, and these differences were ameliorated by chronic lithium treatment. These findings support the hypothesis that impaired inhibition of GSK3 contributes to the pathogenesis of FXS and support GSK3 as a potential therapeutic target.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Avoidance Learning / drug effects
  • Avoidance Learning / physiology*
  • Disease Models, Animal*
  • Fragile X Mental Retardation Protein / genetics
  • Fragile X Mental Retardation Protein / metabolism
  • Fragile X Syndrome / drug therapy*
  • Fragile X Syndrome / enzymology*
  • Fragile X Syndrome / genetics
  • Glycogen Synthase Kinase 3 / antagonists & inhibitors
  • Glycogen Synthase Kinase 3 / metabolism*
  • Lithium Chloride / pharmacology
  • Lithium Chloride / therapeutic use*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout


  • Fmr1 protein, mouse
  • Fragile X Mental Retardation Protein
  • Glycogen Synthase Kinase 3
  • Lithium Chloride