Short communicationImpulsivity trait in the early symptomatic BACHD transgenic rat model of Huntington disease

- Different forms of impulsivity were assessed in early symptomatic BACHD rats (line TG5), a transgenic rat model of Huntington's disease (HD).
- BACHD rats showed high levels of choice impulsivity favoring “smaller, sooner” over “larger/later” rewards (delay discounting task).
- BACHD rats also exhibited a lack of behavioral inhibition indicated by bursts and premature responses in a DRL task assessing action impulsivity.
- Our study is the first to provide evidence of deficits in impulse control in a rodent model of HD.
- These results are relevant to psychiatric alterations in early symptomatic HD patients. They increase the face-validity of the BACHD rat model.

Impulsivity trait was characterized in 3-5 months old BACHD rats, a transgenic model of Huntington disease, using (1) the delay discounting task to assess cognitive/choice impulsivity, and (2) the Differential Reinforcement of Low Rate of Responding task to evaluate motor/action impulsivity. Transgenic animals showed a high level of choice impulsivity and, to a lesser extent, action impulsivity. Our results provide the first evidence that the transgenic BACHD rat (TG5 line) displays impulsivity disorder as early as 3 months old, as described in early symptomatic HD patients, thus adding to the face validity of the rat model.