Immunohistochemical Analysis
Immunohistochemical analysis of striatal projections was limited to the substantia nigra and the ventral half of the putamenopallidal complex because of poor preservation of the dorsal half of this block. Staining was excellent in the ventral half of the putamen, ventral two thirds of the external globus pallidus, nearly the entire internal globus pallidus, and the substantia nigra. The poor staining in the dorsal putamenopallidal block did not bias analysis because there is no difference between dorsal and ventral neuropeptide immunoreactivity in normal persons. The specimen from the patient with presymptomatic Huntington's disease showed abnormalities of enkephalin-immunoreactive fibers in the external globus pallidus