Striatal extracts from patients with Parkinson's disease promote dopamine neuron growth in mesencephalic cultures.

The caudate, putamen, and cerebellum from five patients with Parkinson's disease (PD) and five normal, aged controls were studied to determine if cell-free extracts from these tissues influenced dopamine neuron growth in culture. Cultures incubated with extracts of the caudate and putamen, but not the cerebellum, from PD patients contained more tyrosine hydroxylase immunoreactive neurons than aged controls. These data suggest that the parkinsonian striatum compensates for dopamine loss by increasing neurotrophic factor production.