The BACHD rat model of Huntington disease shows slowed learning in a Go/No-Go-like test of visual discrimination.

Abstract

Huntington disease is a hereditary neurodegenerative disease, in which patients display a broad range of clinical symptoms. Among these, impaired inhibitory control has been noted. The BACHD rat is a recently developed and established transgenic animal model for Huntington disease, and characterizing the presence of Huntington disease-like behavioural phenotypes in these animals is of importance. Prior studies have indicated that BACHD rats suffer from impaired inhibitory control, although further studies are necessary to fully understand the scope and specific nature of these phenotypes. In the current study, BACHD rats were trained to perform a Go/No-Go-like test of visual discrimination, akin to behavioural tests that have revealed suspected response inhibition impairments in Huntington disease patients. The results indicate that although BACHD rats showed a slow rate of learning to inhibit responses on No-Go trials, once they had learned to handle the basic discrimination, they had an unchanged ability to withhold lever responses during extended periods of time. This suggests that BACHD rats have specific impairments when applying inhibitory control to a new or changed situation. The findings are in line with previous studies of BACHD rats and support the continued use and characterization of this animal model.