Abstract:

Objective To investigate how chronic cold exposure influences mitochondrial quantity in cortical neurons and to explore its mechanism with a mice model. Methods Forty male mice of the age of 8 weeks were randomly divided into the control and cold exposure groups. Cold exposure group as an animal model was fed at temperature from -4℃to 0℃ for 4 weeks, and the control group lived in the standard laboratory situation. Mitochondria of granular cells in cerebellar cortex in vivo were labeled with MitoTracker, and the expression of mitochondrial fission and fusion proteins and peroxisome proliferators-activated receptor-γ coactivator-1α (PGC-1α) were analyzed with immunocytochemistry and Western blotting. Results Compared with the control group, the number of mitochondria increased (P<0.01) and the expression of mitochondrial fission, fusion protein and PGC-1α significantly increased (P<0.01) in the cold exposure group. Conclusion Chronic cold exposure may enhance mitochondrial biosynthesis to increase the quantity of mitochondria by activating PGC-1α, while activated PGC-1α can induce the expression of mitochondrial morphology regulatory proteins under cold stress. The new balance of fission and fusion of mitochondria is established at cold environment, leading to adapt to cold situation.

Key words: Cold, Stress, Cerebellar cortex, Granular cell, Mitochondria, Biosynthesis, Western blotting, Mouse