The zona incerta is important for anxiety-mediated behaviors. It contains a group of dopaminergic cells that coexpress the vesicular GABA transporter, potentially coreleasing dopamine and GABA. The superior colliculus is a known projection site of the zona incerta and supports anxiety-driven behavior. However, it is not known if dopaminergic zona incerta cells innervate the superior colliculus via dopamine and GABA transmission. We expressed channelrhodopsin in zona incerta neurons of Th-cre mice, and their fibres were restricted to the medial motor-related layers of the superior colliculus. The superior colliculus cells received monosynaptic GABA transmission from the zona incerta, and these connected cells were dopamine responsive. These results indicated a direct connection between the zona incerta dopamine-GABA cells and the medial motor layers of the superior colliculus. These results are important in understanding the role of the zona incerta dopamine-GABA cells in the regulation of anxiety-related behaviors in the superior colliculus.
K. Schumacker iii
AcknowledgementsThis study was funded in part by the Natural Science and Engineering Council Canadian Graduate Scholarship.To start, I would like to thank my thesis committee for taking the time to read and provide feedback on my thesis, as well as participate in my prospectus and defense.I would like to acknowledge all the researchers who aided me through my degree as well as the members of my lab. First and foremost, I would like to thank my supervisor Dr. Melissa Chee, who helped develop my love for research and mentored me into the researcher I have become. I would like to recognize those who contributed to our previous findings published in the Journal of Comparative Neurology (2020), which formed the basis of this project, including