HDAC6 and Cognitive impairment: In contrast, we observed that the deletion of HDAC6 did not ameliorate any of the major early HD phenotypes: it did not affect the body weight loss, the cognitive impairments, and nest-building deficits shown by R6/1 mice at both 2 and 3 months, while it actually worsened social abnormalities observed at 3 months of age.