Research Of The Correlation Between GABA_B Receptor And Morphine Dependence By Behavior Method And FMRI

Objective:To establish models of morphine dependent rats with conditional Place Preference method research the effects of the GABA_B receptor agonist baclofen on morphine withdrawal signs by behavioral methods and fMRI technique.We discuss the effects of the GABAb receptor Psychological and physical dependence.by opioid and provides a theoretical rational for evaluating baclofen as a potential opioid pharmacotherapy.Method:CPP models of morphine dependent rats were established by intraperintoneal injection and combined with environmental stimulation (1)record the time in drug place and the signs of morphine withdrawal (2)On the foundation of localization by the methods of anatomy stereoscopic localization, we inject 200nL of 80mly by a minim-injector.Then we measure the value of the a activities in OFC by the Image Analysis System of fMRI, .All dates were analysed by statistical method .In the end we research the effect of intervene by baclofen on morphine dependence.ResuIt:Rats of morphine dependent groups appeared conspicuous withdrawal symptoms and withdrawal syndrome scores were significantly higher than that of group of intervened by baclofen .The time in drug place of baclofen intervene group exhibited respectively significantly shorter than the morphine group morphine administration 5~th day, 9~th day and withdrawal 1~st day 3~rd day, however at the withdrawa1.5~th day,10~th day the time in drug place didn't show significant reduction than morphine group The result of withdrawal signs :some signs of morphine withdrawal in baclofen intervene group(ie:wet dog shakes, teeth chattering, ptosis, rearing ,writhing stretching) exhibited respectively significantly lower than the morphine group at morphine withdrawal 1~st day 3~rdday and 5~th day. The result ofactivities in OFC by fMRI technique :The value of activities in baclofen intervene group exerted significantly lower than the morphine group (p<0.01) at morphine withdrawal 3rdday.Conclution: l.CPP models of morphine dependent rats were established successfiilly by intraperintoneal injection with the dosage we explored by experience from referring many paper . 2.The experiment results indicate that the GABA system plays an important role in the procession of morphine dependence. And the antagonist of the GABA could be applying to the clinic for treating drug dependence. 3. The result of fMRI is consistent with the behavior indicate that fMRI could beacted as a detecting instrument in clinic.