Effect of lateral cerebroventricular injection of Orexin A on swimming

Introduction: Orexin A is a hypothalamic neuropeptide, widely distributed in many parts of the central nervous system and perhaps due to this reason, this neuropeptide is involved in many physiological functions. The purpose of this study was to determine the effect of lateral cereberoventricular injection of orexin A on distance, velocity and swimming time in rats. The results were analyzed by one way ANOVA and Tukey HSD tests. P≤ 0.05 was considered as the level of significance. Methods: 30 adult male Wistar rats (200 ± 20 g) were randomly divided into three groups of orexin, sham and control. The orexin and sham groups were placed in a stereotaxic apparatus and a cannula was inserted into their right cerebral ventricle. Lateral cerebroventricular injections were performed with 3 nmol orexin A and 3 nmol aCSF in orexin and sham groups, respectively. Afterwards, rats of 3 groups individually swam for 30 minutes and the distance, velocity and swimming time were measured by Etheovision. Results: Lateral cerebroventrivular injection of orexin A caused significant increases in distance and velocity of swimming, however, it had no effect on swimming time. Conclusion: Lateral cerebroventricular injection of orexin A significantly increased distance and velocity of swimming, without any effect on swimming time in rats.