Expression of c-fos in the regions of frontal lobe related to movement in rats after long-term swimming exercise

Objective To explore the effect of long-term swimming exercise on c-fos expression in the regions of frontal lobe related to movement in rat.Methods Fifty-five male Sprague-Dawley rats were divided into control group(group A),endurance exercise group(group B)and interval exercise group(group C).The rats in groups B and C were trained by different types of swimming for 6 weeks.At 0,30,60,120,240 min after the last swimming exercise,the rats in groups B and C were anesthetized with sodium pentobarbital and perfused transcardially with heparinized physiological saline followed by 4% paraforaldehyde in 0.1 mmol/L phosphate buffer,while the rats in control group were anesthetized and perfused at the first time point.The brains were removed.The expression of c-fos protein was determined by immunocytochemical method.Results The expression of c-fos in rat primary motor cortex(M1)were maximal at 30 min in groups B and C.In secondary motor cortex(M2),the expression of c-fos peaked at 60 min in group C,but there was not obvious changes in group B.In nucleus accumbens(A),the maximum of c-fos presented at 60 min in group C,however,the expression increased continually until 240 min in group B.Conclusion The expression of c-fos after swimming exercises in rat motor cortex and nucleus accumbens may involve in the mechanism of central fatigue and recovery.