STRIATAL DOPAMINE AND SEROTONIN ENCODE BILATERAL SENSORIMOTOR DECISION MAKING

The dorsolateral striatum (DLS) plays a central role in integrating motor and sensory information, yet the neuromodulatory interactions that shape its function remain poorly understood. While dopamine (DA) innervation in the striatum has been extensively studied and is well established in motor control and reward, serotonin (5-HT) innervation has received comparatively less attention. Notably, 5-HT terminals are positioned in close proximity to DA terminals, hinting at a potential but overlooked interaction between these systems. Here, we used fiber photometry to record bilateral DA release in the DLS during a sensorimotor decision-making task in which mice learned to turn a steering wheel based on visual cues. Our findings reveal that while DA signals are largely correlated across hemispheres, interhemispheric asymmetry is directly linked to movement onset. Additionally, and consistent with previous reports, DA responses in naïve animals were reward-related but shifted to stimulus presentation after task proficiency was achieved. To further investigate neuromodulatory dynamics, we recorded 5-HT release during the same task. Our preliminary findings indicate 5-HT signals related to movement onset and reward, suggesting a broader role in sensorimotor processing. These preliminary results provide new insight into the dynamics of DA and 5-HT release in the striatum and their respective contributions to sensory, motor, and reward-related functions. Moving forward, we will simultaneously record DA and 5-HT release and use cell-type-specific perturbations to further dissect their functional interactions.