Effect Of Compound Ketamine Oral Solution On NR2BR And GABAaR In Amygdala Neurons Of Immature Rats In Fear Conditions

ObjectiveTo observe the effect of compound ketamine oral solution (CKOS) onN-methyl-D-aspartate 2B Receptor (NR2BR) and gamma-aminobutyric acid a receptor(GABAaR) in amygdala neurons and the behavioral response of immature rats in fearconditions.Materials and Methods1,Experimental animalsOne hundred male Wistar rats were obtained from Laboratory Animal Center ofChina Medical University, aging 5～6 weeks,weighting 135～145g.2,Animal groupingOne hundred male Wistar rats were randomly divided into 5 groups(n=20each)receiving intragastric administration of saline(control group and modelgroup),compound ketamine oral solution (CKOS group),ketamine oral solution (Kgroup) and mitazolame oral solution (M group)(2μl/g). Intragastric administrationcame 25 minutes before fear conditioning train(control group receiving only sound). 10rats were randomly taken from each group after the last training.Removing brain andchecking the expression of NR2BR and GABAaR in amygdala neurons of immature rats. Freezing Behavior of the other rats was observed 48 hours afer training.3,Fear conditioning modelThe rats were placed in a shock cage,shocked(0.5mA; 0.5s) in the last 0.5 secondsof the sound(75dB; 1000Hz; 5s).It remained one time per minute,18 times per day, 4days in all.rats of control group received only sound but no shock in the sameconditions.4,DetectionFear response were checked with Freezing Behavior and Immunehistochemistrstaining were used to check the expression of NR2BR and GABAaR inamygdala neurons of fear immature rats.5,Statistical analysisStatistical analysis was performed with SPSS12.0. Satistical comparisons weredone using two-tailed t tests(between two groups) or ANOVA(in groups).Ingroups,LSD was used to check the differences between two groups.ResultsComparing control group with model group, freezing was significantlyincreased(P＜0.01), the expression of NR2BR decreased as well (P＜0.01) and theexpression of GABAaR increased (P＜0.05);As compared with model group, freezingwas significantly decreased in CKOS group, K group and M group(P＜0.01 or P＜0.05),the expression of NR2BR decreased in CKOS and K goups(P＜0.01 or P＜0.05) and theexpression of GABAaR increased in CKOS and M goups (P＜0.01 or P＜0.05); AmongCKOS, K and M groups, the score of freezing of CKOS group was lowest,and that of Mgroup lower than that of K group(P＜0.05). In the 3 groups, the expression of NR2BR ofCKOS group was significantly less than that of K group(P＜0.01). However, theexpression of GABAaR of CKOS group was significantly more than that of Mgroup(P＜0.01).Conclusion (1) The expression of NR2BR decreased and that of GABAaR increasedsignificantly in amygdala neurons of immature rats with CKOS intragastricadministration.(2) CKOS effectively blocks sound fear conditioning of immature rats.