Cell type-specific neuronal loss in the putamen of patients with multiple system atrophy.

Using antibodies to calcineurin (CaN) and choline acetyltransferase (ChAT), we performed topographical and cellular immunohistochemical analysis on the posterior putamen of autopsied patients with multiple system atrophy with predominant parkinsonism (MSA-P). We document that in these patients, medium spiny neurons positive for CaN were severely depleted in the dorsolateral portion of the posterior putamen where ChAT-positive neurons are normally distributed. Our findings indicate that in patients with MSA-P, striatal neurons manifest a cell type-specific vulnerability to neurodegeneration.