is the thalamus part of the basal ganglia
Basal ganglia The basal ganglia (or basal nuclei) is a group of subcortical nuclei, of varied origin, in the brains of vertebrates including humans, which are situated at the base of the forebrain. 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, routine behaviors or "habits" such as teeth grinding, eye movements, cognition,[1] and emotion.[2]
Substantia nigra The substantia nigra is a basal ganglia structure located in the midbrain that plays an important role in reward and movement. Substantia nigra is Latin for "black substance", reflecting the fact that parts of the substantia nigra appear darker than neighboring areas due to high levels of neuromelanin in dopaminergic neurons.[1] It was discovered in 1784 by Félix Vicq-d'Azyr,[2] and Samuel Thomas von Sömmerring alluded to this structure in 1791.[3] Parkinson's disease is characterized by the death of dopaminergic neurons in the substantia nigra pars compacta.[4]