ABSTRACT

This chapter reviews the anatomy, connectivity, and the biochemistry of the basal ganglia (BG). It presents some of the models of the way the BG connect with the rest of the brain and how the BG nuclei function together. The basal ganglia are a set of interconnected nuclei located in the base of the forebrain. They consist of the ventral striatum, the dorsal striatum, the globus pallidus – both the internal (GPi) and external (GPe) sections, the substantia nigra pars compacta (SNc) and the substantia nigra pars reticulata (SNr), and the subthalamic nucleus (STN). Anatomical and physiological research supports the contention that the BG are part of a series of separate but parallel circuits that funnel projections from broad sections of the cortex into discrete sections of the BG and then back to even more discrete sections of the cortex. The BG is a complex system of subcortical nuclei involved in the control of movement, cognition, and motivation.