Objective: To observe the distribution of hypoxia inducible factor-1alpha (HIF-1alpha) in different brain regions in aged rats and investigate the role of HIF-1alpha in the aging process of the nervous system.
Methods: The Nissl bodies and HIF-1alpha expression in different brain regions were observed in rats aged 3 and 30 months using Nissl staining and immunohistochemical method, respectively.
Results: In the 30-month-old rats, the neural cells in 4 different brain regions presented with large cell body and loose alignment, containing reduced Nissl bodies in the cytoplasm. Compared with the 3-month-old rats, the aged rats showed greater number of HIF-1alpha-positive cells in the brain (P < 0.01), and the number varied significantly between the different brain regions (P < 0.01). The CA3 region contained the greatest number of positive cells, which were fewer in the motor cortex and cerebellum.
Conclusion: The capacity for protein synthesis in the neural cells is weakened but the expression of HIF-1alpha increased in aged rats, suggesting the important role that HIF-1alpha may play in the aging process of the nervous system, especially in hypomnesis.