Abstract: Objective: This study was designed to discuss the relationship between cell apoptosis of the frontal lobe induced by one-time overload exercise and the changes of mitochondrial morphology in rats,as well as the expression of Drp1、Mfn2, which are associated with mitochondrial fusion and division. Methods:48 male SD rats were randomly divided into control group(group C,n=18),one-time overload exercise group(group E,n=54). Group E was divided again into different groups based on time(immediately,24h and 48h),named group E0,E24 and E48, with 18 rats in each group.Group E: carried out one-time exhaustive swimming for 4 hours.The morphological structure of the loubusfromatis neurons and mitochondria were observed by using transmission electron microscopy, the apoptosis index (AI) detected by TUNEL method, and the mRNA and protein level of Drp1 and Mfn2 detected.Results:the rats’ frontal lobe neurons and mitochondrial appeared irregular after one-time overload exercise,but this exception returned to normal in 48hours. There was a significant reduction of AI in group E, when compared with group C(P<0.01).When compared with the AI at different time points in group E,we can see that E24>E0>E48(P<0.05). The transcription and protein expression of Drp1 and Mfn2 were significantly increased after one-time exhaustive exercise, when compared with group C(P<0.05).The Drp1 transcription and protein expression of group E48 decreased significantly (P<0.05),and the Mfn2 transcription and protein expression decreased slighter (P>0.05), when compared with group E24.Conclusion: Suggest that one-time overload movement cause an abnormal mitochondria morphology and induce cell apoptosis of the loubus fromatis. But in 48 hours tissue damage of the loubus fromatis can be reduced, or even recovery. The expression of Drp1 and the loubus fromatis cell apoptosis induced by exhaustion exercise were closely related. However, the increased expression of Mfn2 could ameliorate the development of the loubus fromatis cells apoptosis caused by exhaustion movement.

Key words: Frontal Lobe, Mitochondrion, Swimming, Drp1, Mfn2