HTT and Huntington disease: While no full-length HD mouse models experience similar pronounced neurodegeneration, a number of imaging30,35,36 and molecular analyses37 confirm that the caudoputamen is the most strikingly impacted brain region in mice expressing mutant Htt. In humans, focal ischemic basal ganglia damage is associated with a range of motivational deficits38, including notable deficits in incentive motivation - the process of activating specific behavioral responses based on predicted reward39.