page_title: Basal ganglia
section_title: Substantia nigra
hierarchical_section_title: Basal ganglia / Structure / Substantia nigra
caption_attribution_description: English: Basal Ganglia. See a related animation of this medical topic.
context_page_description: The basal ganglia are a group of subcortical nuclei, of varied origin, in the brains of vertebrates, including humans, which are situated at the base of the forebrain and top of the midbrain. There are some differences in the basal ganglia of primates. Basal ganglia are strongly interconnected with the cerebral cortex, thalamus, and brainstem, as well as several other brain areas. The basal ganglia are associated with a variety of functions, including control of voluntary motor movements, procedural learning, habit learning, eye movements, cognition, and emotion.
  The main components of the basal ganglia – as defined functionally – are the striatum, consisting of both the dorsal striatum and the ventral striatum, the globus pallidus, the ventral pallidum, the substantia nigra, and the subthalamic nucleus. Each of these components has a complex internal anatomical and neurochemical organization. The largest component, the striatum, receives input from many brain areas beyond the basal ganglia, but only sends output to other components of the basal ganglia. The pallidum receives input from the striatum, and sends inhibitory output to a number of motor-related areas.
context_section_description: The substantia nigra is a midbrain gray matter portion of the basal ganglia that has two parts – the pars compacta (SNc) and the pars reticulata (SNr).  SNr often works in unison with GPi, and the SNr-GPi complex inhibits the thalamus. Substantia nigra pars compacta (SNc) however, produces the neurotransmitter dopamine, which is very significant in maintaining balance in the striatal pathway. The circuit portion below explains the role and circuit connections of each of the components of the basal ganglia.
caption: Location of the substantia nigra within the basal ganglia
exif: {}