Time course of choice reaction time deficits in the Hdh(Q92) knock-in mouse model of Huntington's disease in the operant serial implicit learning task (SILT)

Behav Brain Res. 2008 Jun 3;189(2):317-24. doi: 10.1016/j.bbr.2008.01.020. Epub 2008 Feb 12.


A range of transgenic and knock-in mouse models of Huntington's disease have been created since identification in 1993 of the disease mutation in the HD gene. Knock-in models that express the full-length mutant protein tend to exhibit less severe behavioural deficits than transgenic models and so require more sensitive tasks in order to reveal impairments. To achieve this, we therefore used a Serial Implicit Learning Task (SILT), which measures serial reaction times to visual stimuli, requiring detection and responding in both predictable and unpredictable locations in the 9-hole operant chamber. We have previously reported that knock-in Hdh(Q92/Q92) mice exhibit a modest impairment in learning the SILT tasks at 4 months of age, prior to the formation of overt neuronal nuclear inclusions. In the present study we have explored the time course of the development of impairments from 5 to 14 months of age. The deficit previously found in accuracy and reaction time was present at all ages examined in these Hdh(Q92/Q92) mice; the deficit was not progressive, and did not correlate with the evolution of neuronal nuclear inclusions.

Publication types

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

MeSH terms

  • Age Factors
  • Animals
  • Brain / metabolism
  • Brain / pathology
  • Choice Behavior / physiology*
  • Conditioning, Operant / physiology
  • Disease Models, Animal
  • Female
  • Huntingtin Protein
  • Huntington Disease / genetics
  • Huntington Disease / metabolism
  • Huntington Disease / physiopathology*
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mice, Neurologic Mutants
  • Mice, Transgenic
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Photic Stimulation
  • Probability Learning
  • Psychomotor Performance / physiology*
  • Reaction Time / physiology*
  • Serial Learning / physiology*
  • Species Specificity


  • Htt protein, mouse
  • Huntingtin Protein
  • Nerve Tissue Proteins
  • Nuclear Proteins