[Neurochemical aspects of spinocerebellar degeneration]

Spinocerebellar degeneration (SCD) is one of the most frequent neurodegenerative disorders in Japan. In spite of this, only a little attention has been paid on the disease, especially from the biochemical point of view. In this symposium, I would like to briefly review the fruits of biochemical researches in Japan. GABA, glutamate and aspartate in the cerebellar system of SCD patients disclosed decreases corresponding to the neuronal cell loss in, for instance, the dentate nucleus for GABA. However, it is interesting to know that in case of choline acetylase, its activity in the cerebellar system in CCA increases greatly corresponding to the reservation of cholinergic ponto-cerebellar system. Since the ponto-cerebellar system in CCA is morphologically preserved, this may be a reflection of a compensatory response to the degeneration of cortical cerebellar systems. Finally, I would like to demonstrate a significant decrease of homocysteic acid concentrations in the cerebellar cortical tissues, but not in olive, dentate in OPCA.