They contain GABA, taurine, and a number of neuropeptides and are lost in the disease Huntington's chorea.
Aspiny neurons are of two sizes.
Large and small. The large variety contains acetylcholine and are also lost in Huntington's chorea. The two compartments differ in their input, output, neurotransmitters, and neuromodulators. Other mosaic-like compartments have also been identified. The internal segment of globus pallidus and substantia nigra pars retriculata are morphologically and chemically similar.