Reduction of the size of the Golgi apparatus of spinal anterior horn cells in patients with X-linked spinal and bulbar muscular atrophy

The Golgi apparatus (GA) of spinal anterior horn cells was examined immunohistochemically in five patients with X-linked spinal and bulbar muscular atrophy (SBMA), in five patients with sporadic amyotrophic lateral sclerosis (ALS) and in five patients without neurodegenerative diseases. In SBMA cases, reduction of the size of the GA was observed in numerous anterior horn cells; however, fragmentation of the GA, previously described in sporadic and familial ALS with SOD1 mutations, was observed only in a few neurons. In addition, motor neurons bearing an intranuclear inclusion showed a normal network of elements of the GA. The frequencies of fragmented GA in counted motor neurons were 0-2.4 % in SBMA cases, 0-3.0 % in normal control cases and 15.7-55.3 % in ALS cases. The different frequency of fragmented GA between SBMA and ALS adds another finding of pathogenetic difference of neurodegeneration in these two motor neuron diseases.