Basal ganglia: Basic principles

The full range of basal ganglia functions is still uncertain, but they are principally concerned with the release and suppression of cortically generated movements. They are phylogenetically old, being present in all vertebrates including the reptiles, which have essentially no neocortex. It is likely therefore that their function was originally related to aspects of motivation and homeostasis, mediated by the allocortex (limbic cortex, amygdala, and hippocampus). More recently, they have become closely associated with the neocortex (frontal sensory and motor cortices) and therefore provide a link between cognitive processes and movement.