Sensorimotor integration is the process of collecting sensory stimuli from our environment and transforming it into motor actions to generate behaviors critical for our survival. The dorsolateral striatum (DLS) serves as a primary hub for this process, receiving convergent excitatory inputs from the primary somatosensory (S1) and primary motor (M1) cortices, that encode our sensations and movements, respectively. Despite the DLS’s established role in habit formation and motor execution, how S1 and M1 corticostriatal projections are integrated together by striatal circuitry to produce behavior is less understood. This dissertation investigates the cell-type specific connectivity of S1 and M1 corticostriatal projections to the DLS, and their role in sensorimotor integration and behavior. Using a multi-modal approach, integrating anatomical circuit mapping, ex-vivo electrophysiology, and optogenetic reward-based paradigms, we reveal a significant bias in the corticostriatal circuitry. We demonstrate that the dorsolateral striatum (DLS) functions as a sophisticated filter where M1 provides high-density motor drive via its strong connectivity to spiny projection neurons (SPNs), while S1 inputs are filtered by an inhibitory gate mediate through parvalbumin fast-spiking interneurons (FSIs). Through anatomical clustering and pathway-specific plasticity, the circuit ensures that motor programs are only released when sensory signals achieve sufficient network-level salience to overcome this local suppression. Functional experiments confirm that M1 and S1 corticostriatal inputs elicit divergent influences on sensorimotor learning, and that isolated sensory inputs are insufficient to drive behavior. These findings provide a framework for how sensorimotor integration is achieved through cell-type specific differences in corticostriatal connectivity and has implications for improving human health and sensorimotor disorders.
Branden Dennis Sanabria (2026) studied this question.