Grant: Doctoral: Vanier Canada Graduate Scholarships

Parkinson's disease (PD) is a fatal and incurable degenerative disorder of the central nervous system that affects more than 6.3 million people worldwide. PD is initially associated with movement-related symptoms such as rigidity, slowness of movement, and difficulty with walking and gait. As the disease progresses, cognitive and behavioral deficits can also occur. Despite increased interest, PD treatment options remain limited, and are associated with severe side effects and decreased efficacy over time. Three obstacles hinder development of more effective treatment options: 1) our lack of knowledge of the cortical circuits in a healthy brain which can be involved in PD; 2) incomplete understanding of the pathological changes in neural circuitry during PD; and 3) limited understanding of the neural mechanisms underlying current PD treatments (symptom-based treatment). This study aims to address these obstacles using the saccadic eye movement system in monkeys as a behavioral readout. A saccade is the fast movement of an eye, head, or other animal body part. The saccadic eye movement system is an excellent model for examining changes in the brain, because it is easy to measure, and there is considerable knowledge of the underlying neural circuitry which participates in controlling gaze. Deficits in saccadic eye movements in PD in many ways mirror observed PD motor deficits, and are also improved by current PD treatment options. Since recording eye movements is fast and inexpensive, the saccadic eye movement system is also practical to use in a clinical setting. By training monkeys to perform saccadic eye movements, this study aims to address current obstacles to new PD treatment options by 1) continuing to record interactions between specific areas of the healthy brain which can be involved in PD; 2) recording changes in key brain regions in a PD monkey model; and 3) determining neural activity underlying some current PD treatment options.