Therapy effect of tetramethylphrazim on cognitive impairment after cerebral ischemic injury

doi:10.3321/j.issn:1673-8225.2003.13.001

Abstract：Aim To evaluate the therapeutic effect of active avoidance response on impairment of learning and memory ability after cerebral ischemic injury.Methods 90 Wistar rats were randomly divided into three groups:the control group,the brain ischemic group and TMP-treated group.Each group was observed at 3 time points:the 2nd week,the 4th week and the 2nd month after ischemia.The VD rat model was established by four-vessel occlusion(4VO).The changes of memory ability, LTP and the NMDAR1mRNA expression in the hippocampus were administered by computerized shuttle-training case, extracorporeal hippocampal slices method and in situ hybridization.TMP was injected into abdominal cavity within 5 minutes after the cerebral reperfution.Results Compared with the control group (2nd week:90%± 5% ;4th week:92%± 6% ;2nd month:91%± 6% ),the AAR in the brain ischemic group was significantly lower in the 2nd week(60%± 5% ), the 4th week (40%± 8% ) and the 2nd month (41%± 8% ) (t=1.852,P< 0.05),and it was more obviously at the later two time points(t=2.947,3.504,P< 0.01). In comparison with the brain ischemic group, the AAR of TMP-treated group was absolutely improved(t=1.803,P< 0.05).In the slices of extracorporeal hippocampal CA1 region,LTP detection showed that its injury had happened clearly in brain ischemic group at each time point of the 2nd week,the 4th week and the 2nd month.LTP wave could induce significantly in CO group and TMP group;LTP wave could hardly induce at each time point in BI group.Comparing the percentage of fEPSP slope changes before and after conditioned stimulation,there was a significant difference between CO group and TMP group(t=4.064,3.655,P< 0.01),but no significant difference among each time points; at the 4th week and the 2nd month,it was decreased in each region.Compared with brain ischemic group, significant changes were found in the TMP-treated group at each time point.Conclusion In the early phase of ischemic re-perfusion, TMP can improve impairment of learning and memory.