Age-related behavioural phenotype and cellular characterisation of mice with progressive ablation of D1 dopamine receptor-expressing cells

Abstract

In this study we characterize the behavioural and cellular phenotype of mutant (MUT) mice with progressive loss of D1 dopamine receptor (Drd1a)-expressing cells. Adult [14-19 weeks] MUT mice showed intact working memory in the spontaneous alternation test but evidenced anxiety-like behaviour in the elevated plus maze and the light-dark test. The ethogram of mature adult MUT [average age 22 weeks] was compared with that of young adult MUT mice [average age 12 weeks]. While MUT mice evidenced hyperactivity over initial exploration at both time points, the topography of hyperactivity shifted. Moreover, initial hyperactivity was sustained over habituation at 12 weeks, but not at 22 weeks. Thus, ..