Neuronal loss and plasticity in the supraoptic nucleus in Parkinson's disease.

Disturbed circadian control of renal water excretion and blood pressure adaptation in Parkinson's disease (PD) suggest impaired hypothalamic magnocellular neurosecretion. To test the hypothesis that this may relate to specific hypothalamic pathology in PD, we studied morphometrically the neuronal population of the supraoptic nucleus (SON) in PD patients and controls. Neuronal loss in the SON of PD patients was associated with increased somatic, nuclear, and nucleolar size of remaining neurons, suggesting compensatory response of these cells. We conclude that SON pathology is a feature of PD and may account for specific signs of neurohumoral dysfunction.