Learning in the corticostriatal network

A fundamental question regarding movement control is how the brain regulates motor learning. In other words, how does initially variable control of a new behavior transition into stable control of a skilled behavior? Plasticity in the corticostriatal network, which includes the motor cortex and the striatum, an input structure of the basal ganglia innervated by the motor cortex, has been identified as a critical regulator of learning. In this thesis, I begin by presenting a historical perspective on the motor network, outlining why the corticostriatal network is uniquely positioned to regulate learning. I then present my work investigating the corticostriatal network during learning. In Chapter 2, I explore how the corticostriatal network drives learning of a complex coordinated action and show that distal vs. proximal movements are differentially encoded. In Chapter 3, I examine how and when corticostriatal plasticity occurs during learning and show that non-REM sleep and sleep spindles play central roles in shaping the corticostriatal network. I conclude by presenting a model for motor network organization in Chapter 4, proposing that corticostriatal plasticity may mediate learning by transitioning an initially cortically driven behavior to a subcortically driven behavior