DEFECTS OF CYTOCHROME-C-OXIDASE IN THE SUBSTANTIA-NIGRA OF PARKINSONS-DISEASE - AN IMMUNOHISTOCHEMICAL AND MORPHOMETRIC STUDY

Defects of respiratory chain complexes were considered as possible pat hogenetic mechanisms in Parkinson's disease (PD). Changes of cytochrom e c oxidase (COX) in four different nuclei of the substantia nigra of 8 PD cases and 10 age-matched controls were investigated by means of m orphometry and immunohistochemistry. Pigmented neurons with COX defect s were randomly distributed within the four nuclei of PD cases, but on ly in the posterolateral nucleus was the numerical density of pigmente d neurons with COX defects significantly increased compared with contr ols. The numerical density of pigmented neurons without COX defects wa s significantly reduced in the anteromedial, anterointermediolateral, and posterolateral nuclei in PD. The cell size of pigmented neurons wi th and without COX defects was significantly diminished in the anterom edial and posterolateral nuclei of PD cases. It is suggested that comp lex TV defects in nigral neurons are most probably a result of acceler ated aging, but are least likely to be a primary aspect of the pathoge netic processes occurring in PD.