The Effect of Physical Activity on the Orexin and Brain-derived Neurotrophic Factor Expression on the Kindling Model of Epileptic Rats.

INTRODUCTION

Epilepsy is characterized by recurrent seizures associated with cognitive, mental, and social issues. Exercise has been well known as a non-pharmacological or complementary remedy that reduces the effective dose and side effects of pharmacological therapies. Orexin signaling pathway and brain-derived neurotrophic factor (BDNF) have an essential role in the pathogenesis of epilepsy. In this study, we investigated the effect of exercise on the modulation of the orexin-A (OXA) and BDNF signaling pathways in epileptic rats.

METHODS

Male Wistar rats were divided into 5 groups: Normal saline (NS), seizure, physical activity (PA), PA + pentylenetetrazol (PTZ), and PA-PTZ. Assessment of seizure behaviors was done 30 min after each PTZ injection in the seizure, PA+PTZ, and PA-PTZ groups. Seizure behavior score (SBS) was monitored in seizure, PA+PTZ, and PA-PTZ. The expression of the OXA and BDNF in the CA1, CA3, and cortex was assayed by immunohistochemistry staining. The correlations between the OXA and BDNF were evaluated in the study groups.

RESULTS

SBC was reduced in the epileptic rats that had exercised. Seizure and PA increased the OXA expression in the seizure and PA groups. Compared to the seizure group, the OXA expression decreased in the CA1 and CA3 of the PA+PTZ, PA-PTZ, and cortex of the PA+PTZ group. OXA was up-expressed in the PA-PTZ group compared to the PA+PTZ group. Seizure decreased the BDNF expression in the seizure group compared to the NS group. PA elevated the BDNF expression in the CA1, CA3, and cortex of the PA group. BDNF was up-expressed in the cortex of the PA+PTZ and the CA1, CA3, and cortex of PA-PTZ. BDNF expression increased in the CA1 and CA3 of the PA-PTZ compared to the PA+PTZ group. There was a significant correlation between the OXA and BDNF expression in the CA1, CA3, and cortex of the NS and seizure groups and the CA1 and cortex of the PA group.

CONCLUSION

Our results indicate that PA had an amelioration effect on the severity of the seizure. Our findings suggest that the effect of PA on seizure might not arise from the interaction of the OXA and BDNF expression in epileptic rats.