Levels of mRNA coding for alpha-, beta-, and gamma-synuclein in the brains of newborn, juvenile, and adult rats.

Synucleins are proteins known for their malfunction in a group of illnesses called synucleopathies, which includes Alzheimer's and Parkinson's disease. To learn more about the role of synucleins in the CNS, we have studied levels of message coding for alpha-, beta-, and gamma-synuclein using quantitative RT-PCR. Levels of synuclein mRNAs were studied in the cerebral cortex (left and right, anterior and posterior), hippocampus, striatum, and cerebellum, obtained from 5-d-old (newborn), 1-mo (juvenile)-, and 6-, and 9-mo (adult)-old rats. The mRNA levels for all synucleins varied significantly among structures. The rank order of mRNA levels in different structures was cortex = hippocampus > striatum > cerebellum for alpha-synuclein; cortex > hippocampus = cerebellum > striatum for beta-synuclein; and hippocampus = striatum > cortex = cerebellum for gamma-synuclein. There was significant effect of age for mRNA levels for all synucleins. The dynamics of these changes were different depending on type of synuclein and brain structure. Levels of mRNA for alpha-synuclein were significantly reduced with age in all structures except hippocampus. For beta- and gamma-synuclein, levels increased significantly only in the cerebral cortex and only from 5 d to 1 mo of age. In contrast, gamma-synuclein levels in the cerebellum were very high at 5 d and significantly reduced at 1 mo of age. The revealed pattern and dynamics of changes in the levels of mRNA coding for synucleins would support the conclusion for an important role of these molecules during development and the aging process.