Neuroprotection And Long-Term Efficacy Of The Learning And Menory Of HIE Mild Hypothermia In The Immature Rats

Objective: Dynamic obsercation of neuronal apoptosis and the expression of BDNF in the rats with HIE after mild hypothermia treatment, then throngh the water maze test to investigate the neuroprotective effec and the long-term efficacy of mild hypothermia treatment.Methods:HIBD rat model was established at 7th day, under mild hypothermia (31℃) treatment for 48, icobsercation of neuronal apoptosis with TUNEL staining and the expression of BDNF with OD of immunohistochemistry in the rats with HIE at the 7th day, 1th week and 28th day after the treatment, the water maze test was done at 28th day.Results:(1) Model building: Activities of rats with HIE were model significantly less than the sham operation group 24h after model-building, the eyes of left in rats with HIE test dysplasia at 14d after model-building ; Cerebral edema, cells flake disorder and dead cells flake can be seen by light microscopy in brain specimens of rats with HIE, then that of the sham operation group were normal. (2) Immunohistochemical results: BDNF of the hippocampus was detected by immunohistochemistry at 24h and 1w after treatment of mild hypothermia, the number of the treatment groups was 11215.04±620.48 and 8736.08±495.04, the control groups 920.48±410.02 and 2952.32±245.01,the sham-operated groups 1312.77±176.00 and 1474.74±151.14. BDNF of the treatment groups were higher than the control groups(p<0.05), the treatment groups and the sham-operated groups were not significant difference(p>0.05).(3) TUNEL staining results: Apoptosis of the hippocampal neurons was detected at 24h,1w after treatment of mild hypothermia, the number of the treatment groups was 28.4±4.21 and 22.8±1.92, the control groups was 52.4±6.20 and 37.6±6.58, the Sham-operated groups was 2.01±2.30 and 1.62±4.51,the treatment groups were lower than the control groups(p<0.05); the treatment groups the control groups were not significant difference(p>0.05).(4) Water maze experimental results: All rats were feeded(under the same conditions) to 28 days, Water maze experimental was crarryed on .The results of the escape latency: the treatment groups was 6.858±3.337,the control groups was 51.779±11.778, the sham-operated groups was 4.321±2.355.Compared with the treatment groups, the escape latency of the control groups were longer significantly(p<0.05), then the sham-operated groups were not significant difference(p>0.05); The results of the the Percentage of Platform range: the treatment groups was 59.338±10.817, the control groups was 9.038±5.360, the sham-operated groups was 68.183±8.170. Compared with the treatment groups, the percentage of platform range was less significantly(p<0.05), then the sham-operated groups were not significant difference(p>0.05).Conclusions:(1) The treatment of mild hypothermia for rats with HIE in early time was obvious protection for neuronal, and the effect of protection could maintain more than one week; The performance of the protective effect expression the addition of BDNF and the reduction of apoptosis of the neurons.(2)The treatment of mild hypothermia has significant long-term effects for rats with HIE.