Motor cortex connections

In this chapter, we focus on the connectivity of cortical areas that collectively control voluntary movement, as well as on mechanisms by which this precise connectivity is established. We outline the historical identification of a “motor cortex”, as well as its anatomical and functional organization. We detail the efferent motor cortex connectivity with subcortical motor control centers in the basal ganglia, thalamus, brainstem, and spinal cord. We principally focus on efferent connections with subcerebral targets in the brainstem and spinal cord, for which we describe developmental mechanisms that control this precise connectivity in both experimental animals and humans. We next describe afferent connectivity to motor cortex from the basal forebrain and thalamus, and additionally detail the intracortical connectivity both within motor cortex as well as between motor cortex and other cortical areas. In the last section, we highlight some of the technological advances that will be important for ultimately identifying the detailed molecular development and organization of the primate, and eventually human, motor cortex connectivity.