Effect on learning and memory of immature mnouse with convulsion induced by ropivacaine toxicity

Abstract

Objective To investigate the effect of juvenile convulsion induced by ropivacaine toxicity on adult learing,memory and post synaptic density-95protein(PSD-95) protein expression in rats. Methods Twenty Sprague-Dawley(SD)rats(age=18 d) were randomly divided into ropivacaine group(R group) and saline group(N group)(n=10).Morris water maze was performed on rats in the both groups for 3 days,2 times per day,rats fulfilling the standards were included in the experiments (latency period ≤ 120 s).Rats in the R group were intraperitoneally injected with 33.8 mg/kg ropivacaine,and those in the N group were injected with 0.1 ml/kg saline when rats were 21days old.The rats convulsed were adopted and performed with morris water maze again as before when they were 55 days old,4 days later memory test was performed.The sections of hippocampus were collected at the end of test,PSD-95 expression and post synaptic density(PSD) thickness was detected by Weston Blot and electron microscope,respectively(n=5). Results There was no significant differences in latency between the R group and the N group[d1(12.6±3.4) vs (10.5±4.1) s,d2 (6.8±2.8) vs (7.1±1.3) s,d3 (6.2±0.7) vs (6.4±1.1) s,d4 (5.0±2.7) vs (8.1±4.0) s respectively(P＞0.05)].There was no significant differences in PSD-95(0.6±0.1 ) vs (0.6±0.0) respectively(P＞0.05)and PSD(84±6),(81±7) nm,respectively(P＞0.05)between the R group and the N group. Conclusions There was no significant effect of juvenile convulsion induced by ropivacaine toxicity on adult learing,memory,and PSD-95 in rats. Key words: Ropivacaine; Convulsion; Learning and memory; Post synaptic density-95 protein