Subregion-specific dendritic spine abnormalities in the hippocampus of Fmr1 KO mice

Neurobiol Learn Mem. 2011 May;95(4):467-72. doi: 10.1016/j.nlm.2011.02.009. Epub 2011 Mar 1.


Fragile X syndrome (FXS) is the most common inherited form of mental retardation and is caused by the lack of fragile X mental retardation protein (FMRP). In the brain, spine abnormalities have been reported in both patients with FXS and Fmr1 knockout mice. This altered spine morphology has been linked to disturbed synaptic transmission related to altered signaling in the excitatory metabotropic glutamate receptor 5 (mGluR5) pathway. We investigated hippocampal protrusion morphology in adult Fmr1 knockout mice. Our results show a hippocampal CA1-specific altered protrusion phenotype, which was absent in the CA3 region of the hippocampus. This suggests a subregion-specific function of FMRP in synaptic plasticity in the brain.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CA1 Region, Hippocampal / cytology*
  • CA1 Region, Hippocampal / metabolism
  • CA3 Region, Hippocampal / cytology
  • CA3 Region, Hippocampal / metabolism
  • Dendritic Spines / classification*
  • Dendritic Spines / genetics
  • Fragile X Mental Retardation Protein / genetics
  • Fragile X Mental Retardation Protein / metabolism*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Pyramidal Cells / cytology
  • Pyramidal Cells / growth & development*
  • Pyramidal Cells / metabolism


  • Fmr1 protein, mouse
  • Fragile X Mental Retardation Protein