Operant-based instrumental learning for analysis of genetically modified models of Huntington's disease

Huntington's disease is the result of an expanded CAG repeat in the gene that codes for the protein huntingtin and results in a progressive sequelae of motor, cognitive and psychiatric symptoms. The development of genetically modified rodent models of Huntington's disease has led to the need for sensitive behavioural phenotyping. Operant tests for rodents have been developed that can determine the functional deficits in these genetically modified models, from motor, cognitive and emotional domains. The current review discusses tests that employ operant equipment, an automated and highly flexible method for testing rodents. Different operant paradigms are examined in relation to their relevance to Huntington's disease symptomology, as well as summarising research to date on genetic models with these tests.