Impaired spatial processing in a mouse model of fragile X syndrome

Behav Brain Res. 2018 Sep 17;350:72-79. doi: 10.1016/j.bbr.2018.05.012. Epub 2018 May 17.


Fragile X syndrome (FXS) is the most common form of inherited intellectual impairment. The Fmr1-/y mouse model has been previously shown to have deficits in context discrimination tasks but not in the elevated plus-maze. To further characterize this FXS mouse model and determine whether hippocampal-mediated behaviours are affected in these mice, dentate gyrus (DG)-dependent spatial processing and Cornu ammonis 1 (CA1)-dependent temporal order discrimination tasks were evaluated. In agreement with previous findings of long-term potentiation deficits in the DG of this transgenic model of FXS, the results reported here demonstrate that Fmr1-/y mice perform poorly in the DG-dependent metric change spatial processing task. However, Fmr1-/y mice did not present deficits in the CA1-dependent temporal order discrimination task, and were able to remember the order in which objects were presented to them to the same extent as their wild-type littermate controls. These data suggest that the previously reported subregional-specific differences in hippocampal synaptic plasticity observed in the Fmr1-/y mouse model may manifest as selective behavioural deficits in hippocampal-dependent tasks.

Keywords: Cornu ammonis 1; Dentate gyrus; Fmr1(−/y) mouse; Fragile X syndrome; Hippocampus; Metric change; Temporal order.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Discrimination, Psychological / physiology
  • Disease Models, Animal
  • Fragile X Syndrome / physiopathology
  • Fragile X Syndrome / psychology*
  • Hippocampus / physiopathology
  • Male
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Motor Activity / physiology
  • Spatial Processing* / physiology
  • Time Perception / physiology