Orexin-A On Consciousness And Expression Of RasGRF1 In Prefrontal Cortex Of Coma Rats Induced By Traumatic Brain Injury

Objective:To study the effect of orexin-A on wake-promoting and the expression of Ras-guanine nucleotide releasing factor-1(RasGRF1)in the prefrontal cortex of comatose rats with traumatic brain injury(TBI).Methods:60 Sprague-Dawley rats were randomly divided into control group,model group,low dose group,medium dose group and high dose group.TBI models were established by weight-drop head injury.The control group and model group were injected with artificial cerebrospinal fluid,low dose group were injected with 1nmol Orexin-A,medium dose group were injected with 3nmol Orexin-A and high dose group were injected with 5nmol Orexin-A.The behaviors of rats were observed according to righting reflex and record the number of wakeful rats,Western-blot and immunohistochemistry technique were used to detect the expression of RasGRF1 in the prefrontal cortex of each group.Results:Eight rats awakened in the edium dose group(8/12),four in the low dose group(4/12)and two in the high dose group(2/12).The level of RasGRF1 in prefrontal contex of rats was ranged from low to high as the control group,the model group,the high dose group,the low dose group,the medium dose group(P<0.05).Conclusion:The concentration dependent of Orexin-A can improve the consciousness state of rats after TBI,which may be related to up-regulating the expression of RasGRF1 in prefrontal cortex.