Basal ganglia neuronal nitric oxide synthase mRNA expression in Parkinson's disease

Expression of nitric oxide synthase (NOS) mRNA in post mortem brain was studied in putamen, globus pallidus and subthalamic nucleus (STN) of neurologically normal control subjects and patients with Parkinson's disease (PD) using in situ hybridization histochemistry. In PD, a significant increase in NOS mRNA expression was observed in the dorsal two-thirds of the STN with respect to the ventral one-third of the STN. A significant increase in NOS mRNA expression per cell in the medial medullary lamina of the globus pallidus was also observed in PD. NOS mRNA expression was significantly reduced in PD putamen. These findings provide evidence of increased activity of STN neurotransmitter systems in PD and demonstrate for the first time in any species that basal ganglia nitric oxide systems can be selectively regulated in response to changes in dopaminergic input.