Immunohistochemical study on the distribution of alpha-synuclein in the central nervous system of transgenic mice expressing a human Cu/Zn superoxide dismutase mutation

We used the SOD1^G93A transgenic mice as an in vivo model of amyotrophic lateral sclerosis (ALS) and performed immunohistochemical studies to investigate whether α-synuclein is involved in the pathogenesis of ALS. In the spinal cord of transgenic mice, immunohistochemistry showed intense staining of α-synuclein mainly in the anterior horn. In the hippocampus of transgenic mice, differential increases in the staining density of α-synuclein were observed. In the cerebellar cortex of transgenic mice, the prominent immunostaining of α-synuclein was found in the molecular and granular layers. The present study provides the first in vivo evidence that α-synuclein immunoreactivity was increased in the central nervous system of SOD^G93A transgenic mice, suggesting that α-synuclein might play an important role in the pathogenesis of ALS. However, the functional implications of these increases require elucidation.