Modulatory effect of exercise on reactive astrocytes in the somatosensory cortex of epileptic rats

BackgroundAstrocytes as the most abundant brain cells play a variety of critical roles in neuroplasticity and normal brain function. Many epileptic patients show changes in astroglia morphology and function named reactive astrogliosis. The beneficial role of exercise has been reported in several studies. This study aimed to assess the effect of regular moderate exercise on astrocytes alteration followed by chronic seizures in the somatosensory cortex.MethodsMale Wistar rats were divided into five groups: sham, pentylenetetrazole (PTZ), exercise (EX), EX before PTZ and EX + PTZ. Animals in the sham group received saline every other day for 4 weeks intraperitoneally (i.p.). Chronic seizures were induced by an i.p. injection of PTZ (35 mg/kg) every other day for 4 weeks. The protocol of exercise was running on a treadmill for 30 min/day 5 days a week at a mild intensity. The mean percentage of GFAP, C3 and S100A10 reacted astrocytes in the somatosensory cortex was assessed using immunohistochemistry.Findings.Our findings indicated that GFAP, as well as S100A10 expression, increased in the EX and the EX before PTZ group. The expression of the C3 receptor as a marker of neurotoxic astrocytes decreased in the three groups of exercise. In addition, the C3/S100A10 ratio in the somatosensory cortex decreased in the three groups of exercise.ConclusionExercise would remodel astrocytes in the somatosensory cortex in favor of producing more neuroprotective astrocytes following the chronic seizure. Further, the improvement of neuroprotective astrocytes may be involved in the antiepileptogenesis effect of preconditioning exercise.