The Effects Of Mu-opioid Receptor Expression In Insular Cortex On Behavioral Changes And CREB Expression In Morphine Addicted Rats

Objective To investigate the effects of mu-opioid receptor expression in insular cortex on learning and memory in morphine addicted rats.Detecting the expression of CREB in insular cortex.Discussing the function of mu-opioid receptor in insular cortex on morphine addicted rats,and the also aimed at providing a perspective and basis on addiction treatment and insular function.Methods The experiment used SD rats as subjects,and provided by the Experimental Animal Center of Medical University,weight between 220-250 g.24 SPF rats were randomly divided into 4 groups(Group Con,Mor,Mor + AAV and Mor+NC).In addition to the normal group,the model of morphine addiction was established in all groups.After that,for the last two groups,microinjection(AAV-MOR,which can silence the expression of MOR and empty carrier AAV)was used bilaterally in Insular cortex.The spatial learning-memory of the rats were observed by intellicage.And the expression of CREB(a protein that related to learning and memory)was observed by immunofluorescence and Western blotting.Results The results of Intellicage showed that the memory of morphine addicted rats was significantly lower than the normal control group(P<0.05).There was no significant difference between the adenovirus treatment group,the morphine addicted group and the empty carrier group(P>0.05).The result of immunofluorescence indicates that there is a wide range of CREB expression in the anterior insular cortex.The results of Western Blotting showed that compared with the normal control the expression of MOR in addicted group was increased.Compare with the Group Mor and Group Mor+NC,the expression of MOR in adenovirus treatment group was decreased,and the difference was significant(P<0.05).As for CREB,the expression in normal control group is obviously.And compare with the Group Mor and Group Mor+NC,the expression of CREB in adenovirus treatment group was increased,the difference was significant(P<0.05).Conclusions Morphine addiction can cause damage to learning and memory in rats.For the rat insular lobe,the inhibition of MOR can increase the expression of CREB,but there is no obvious difference in behavior.