Changes of Neurons in Substantia Nigra of Middle Brain of Rats Associated with the Increasing Age

Objective: To study the regularities of changes of neurons in substantia nigra of middle brain of rats with increasing age. Methods: 32 SD rats were used and divided into four groups: 1～2 months, 4～5 months, 11～12 months and above 24 months. Routine paraffin sections were made for crystal violet staining, terminal transferase and biotin dUTP nick end labeling (TUNEL) staining. The neurons and the TUNEL positive neurons (apoptotic cells) in the substantia nigra were analyzed with morphoretric technique. Results: The numbers of neurons in substantia nigra of middle brain decreased with increasing age ( P0 05 ) and the number of apoptotic cells increased along with the age increasing ( P0 05 ). Conclusion: The increasing decrepit change of neurons in substantia nigra with age increasing might have important implication for the pathogenesis of substantia nigra disease in this region.[