DOPA-DECARBOXYLATION IN THE STRIATA OF RATS WITH UNILATERAL SUBSTANTIA-NIGRA LESIONS

The source and site of the DOPA decarboxylation to dopamine in Parkinson's disease (PD) and animal models of PD are controversial. Since most of aromatic L-amino acid decarboxylase (AADC) are lost along with the degenerating dopaminergic neurons. we addressed the possibility that other decarboxylases or a novel protein that is structurally different from AADC decarboxylate L-DOPA in the denervated striatum. Immunotitration of the extracts from the denervated striatum with AADC antibody showed that all activity can be attributed to AADC-immunoreactive protein. We then investigated if there are non-dopaminergic intrinsic striatal neurons that express AADC. No evidence of such neurons was noted by immunocytochemistry and in situ hybridization.