The striatum, which is the major component of the basal ganglia, displays a complex mosaic
organization of neurochemical systems that are related to its neuroanatomical connections.
This mosaic organization reflects multiple levels of functional compartments. The first level is
determined by the segregation of two major striatal output systems, one to the globus
pallidus (external segment) and the other to the entopeduncular nucleus and substantia
nigra. The second level segregates the cortical outputs of sublaminae of layer V between the …

The basal ganglia provide a major neural system through which the cortex effects behavior.
Most notable among these effects are those related to the voluntary control of movement,
which is compromised by neurodegeneraн tive diseases that involve the basal ganglia. Two
such diseases, Parkinson's disease and Huntington's chorea, display a spectrum of
movement impairн ment (Albin et al 1989). Parkinson's disease, which results in the
degenerн ation of dopaminergic systems in the basal ganglia, produces a disability to …