By Seamus Whitford, Neuropsychology
Advisor: Brittany Smith
Abstract: We are characterizing the SOX8 gene deletion in mice. The deletion results in an impaired direct striatal pathway, and an intact indirect pathway. This direct pathway controls the basal ganglia and voluntary movement control. The gene is noticeably expressed in the brain, testis and spinal cord. SOX8 mutant mice have impaired spatial learning, a reduction in body weight, and are hyperlocomotive. The next step is to see how this deletion affects executive function. Since this deletion may lead to impairments it is thought that the heterzygous SOX8 mutants will not learn as well overtime as the wild types during testing. This testing of executive function involves a five choice serial reaction timed task. The tasks performed by the mice require attention, impulse control, and overall cognitive capacity. We are now testing a sample size of heterozygous SOX8 mutants versus wild types, in both males and females (n = 13-16/group). The test data will measure correct answers and blank/incorrect answers, along with learning rate. This is to see how learning progresses based on effects from this gene. The test mice will also be subject to an individualized 10% reduction in allowed food consumption. This restriction provides the mice to still be hungry and work for food-based rewards offered by correctly completing the tests. So far, the heterozygous SOX8 mutant mice are making significantly fewer correct responses in a basic fixed ratio 1 task but comparable incorrect responses. These results suggest that SOX8 is important for cognition and executive function.