, Volume 215, Issue 2, pp 291–300 | Cite as

Early continuous inhibition of group 1 mGlu signaling partially rescues dendritic spine abnormalities in the Fmr1 knockout mouse model for fragile X syndrome

  • Tao Su
  • Hong-Xing Fan
  • Tao Jiang
  • Wei-Wen Sun
  • Wei-Yi Den
  • Mei-Mei Gao
  • Sheng-Qiang Chen
  • Qi-Hua Zhao
  • Yong-Hong Yi
Original Investigation



Abnormal dendritic spine morphology is a significant neuroanatomical defect in fragile X mental retardation. It has been suggested that overactive group 1 metabotropic glutamate receptor (mGlu) signaling is associated with the spine dysmorphology occurring in fragile X syndrome (FXS). Thus, group 1 mGlu became a new therapeutic target for the treatment of FXS.


The purpose of this study was to identify the effect of inhibition of mGlu signaling in FXS.


We observed the changes in dendritic spines after pharmacological modulation of mGlu signaling in an Fmr1 knockout (KO) mouse model.


The activation of group 1 mGlu resulted in elongation of dendritic spines in the cultured neurons derived from Fmr1 KO mice and wild-type (WT) mice. Antagonism of group 1 mGlu reduced the average spine length of Fmr1 KO neurons. Furthermore, systemic administration of the selective group 1 mGlu5 antagonist 2-methyl-6-phenylethynyl pyridine (MPEP) reduced the average spine length and density in the cortical neurons of Fmr1 KO mice at developmental age. For the adult mice, MPEP administration was less effective for the restoration of spine length. The percentage of immature spines showed a similar reduction in parallel to the changes of spine length. Temporary MPEP intervention with single-dose treatment did not show any effect.


These results show that MPEP administration could partially rescue the morphological deficits of dendritic spines in Fmr1 KO mice at developmental age.


Fragile X syndrome Metabotropic glutamate receptor Dendritic spines Antagonist 



Metabotropic glutamate receptor


Fragile X syndrome




Wild type


2-Methyl-6-phenylethynyl pyridine


Fragile X mental retardation protein




N-Phenyl-7-(hydroxyimino) cyclopropa-[b]chromen-1a-carboxamide



This research was supported by the National Nature Science Foundation of China (grant number 30870876) and the Natural Science Foundation of Guangdong Province of China (grant number 2008B030301250).


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Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Tao Su
    • 1
  • Hong-Xing Fan
    • 1
  • Tao Jiang
    • 1
  • Wei-Wen Sun
    • 1
  • Wei-Yi Den
    • 1
  • Mei-Mei Gao
    • 1
  • Sheng-Qiang Chen
    • 1
  • Qi-Hua Zhao
    • 1
  • Yong-Hong Yi
    • 1
  1. 1.Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and Ministry of Education of ChinaInstitute of Neuroscience and the Second Affiliated Hospital of Guangzhou Medical UniversityGuangzhouChina

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