Effect of orexin-A on learning and memory of pentyleneterazol-kindled epileptic rats

Objective To investigate the effects of orexin-A on learning and memory of pentyleneterazol (PTZ)-kindled epileptic rats.Methods Adult Wistar rats were randomly divided into control group(normal saline,NS)and PTZ group.The PTZ-kindled rats were randomly divided into,orexin-A group and NS group administrated by intracerebroventricular(i.c.v.)injection of 10μl orexin-A(1.4 nmol/μl)or 10μl NS.Using Morris water msze experiment,the ability of learning and memory was measured in all rats.Results Eighty percent of rats in PIZ group were kindled successfully after intraperitoneal injection of 35mg/kg PTZ every day for 30 days.Compared to control group,the escape latency in the PTZ-kindled rats was significantly increased in place navigation test(PNT)(F=200.956,P<0.01),whereas a remarkable reduction of time spent in the target quadrant and number of pool circlings in 120 seconds Was observed during probe trials.Following injection of orexin-A,the latency of escape platform was significantly declined in both PTZ-kindled((39.73±2.03)8,(33.76±2.96)s)and NS rats,increased the number of crossing the platform(10.83±1.80)vs(4.67±3.34).In addition,the treatment with orexin-A markedly increased swim velocity and number of pool circlings in beth groups(P<0.01),particularly to the PTZ-kindled rats.Conclusion Spatial learning and memory in the PIZ-kindled rats can be improved by treatment with orexin-A. Key words: Epilepsy; Orexin-A; Learning and memory