Dissertation Defense Announcement

The College of Arts and Sciences announces the Final Dissertation Defense of

Zade Holloway

for the Degree of Doctor of Philosophy

September 12, 2018 at 10:00 AM in Psychology Building

Advisor: Helen Sable

Cerebellar Modulation of Mesolimbic Dopamine Transmission is Functionally Asymmetrical

ABSTRACT: Cerebral and cerebellar hemispheres are known to be asymmetrical in structure and function, and this asymmetry extends to the mesolimbic dopamine system. In vivo experiments have shown the cerebellum is directly involved in regulation of the dopamine release in the dopamine system by way of contralateral connections from the DN to the VTA. Cerebellar connections to the VTA suggest that the cerebellum modulates dopamine release in the mesolimbic system, yet it is unclear if these pathways are functionally different in each hemisphere of the brain. The current study sought to determine if the mesolimbic dopamine system is asymmetrical between hemispheres, and further to determine if cerebral or cerebellar networks underly this laterality. Using in vivo fixed potential amperometry with carbon fiber recording microelectrodes, Experiment 1 examined left and right DN-NAc pathways to determine if stimulation-evoked dopamine release was functionally asymmetrical. Experiment 2 excluded the cerebellar influence on mesolimbic dopamine release, and instead investigated for asymmetry in left and right MFB-NAc pathways. Our results indicate increased stimulation-evoked dopamine concentrations in the DN-NAc pathway originating in the left cerebellar hemisphere in comparison to the right cerebellar hemisphere. In the cerebral MFB-NAc pathways we found similar dopamine release concentrations, suggesting that the cerebellum has some contribution to asymmetry of the mesolimbic dopamine system. These studies may provide insight about the relationship between the cerebrocerebellar networks and lateralization of the dopaminergic system, as well as potentially reveal novel targets for pharmacological interventions in neuropathology of the cerebellum.