Study On The Proteins Of Neural Network Reconstruction After Hypoxic-ischemic Injury In Piglets

Objects: Hypoxic-ischemic encephalopathy(HIE)in newborns can cause permanent neurological damage or death of the newborns.After brain tissue hypoxia ischemia(HI)damage,the recovery of brain function needs to experience neural network reconstruction process.This process mainly includes the synapse and axon regeneration.This study uses piglet hypoxic ischemic brain damage(HIBD)model,with synaptophysin(Syn)and neurocan(Neu)as the research objects.Through researching the change of the content of the Syn and Neu by histological detection at different time points,this study analyzes the synapse and axon regeneration characteristics in order to further clarify the neural network reconstruction mechanism after HIBD.Methods: The HIBD model of new born Yorkshire pigs was established by blocking the blood flow of bilateral common carotid arteries and mechanically introducing nitrogen oxygen mixture containing 6% oxygen for 40 minutes.The weight of each piglet was about 1?1.5kg,29 in total,4 in the control group and 25 in the HIBD model group.According to the survival time after HI,it was further divided into 6 subgroups(0?2h,2?6h,6?12h,12?24h,24?48h,48?72h),4?5 in each group.The changes of Syn and Neu content in different time points after HI were detected by immunohistochemical staining.The immunohistochemical images were collected and processed by Nikon Edipse E 800 microscope and NIS-Elements F 2.30 image acquisition software.The optical density value(OD value)of the immunohistochemical images was measured by NIS-Elements BR 2.10 image analysis software.The data were statistically analyzed by SPSS 26.0 software.The difference was statistically significant(P<0.05).Results:(1)After HIBD,the expression of Syn in the basal ganglia region of piglet showed an overall trend of increasing first and then decreasing,and reached the peak at 6?12h gruop,then decreased.This suggests that the number of synapses in the basal ganglia region after HIBD first recovered and increased,and then decreased.Compared with the control group,the expression of 0?2h group,2?6h group and 6?12h group increased significantly(P<0.05).And compared with the 6?12h group,the expression of 12?24h group,24?48h group and 48?72h group decreased significantly(P<0.05).(2)After HIBD,the expression of Neu in basal ganglia region of piglet showed an overall trend of decreasing first,then increasing and then decreasing,and reached the trough at 6?12h,then increased,and reached the peak at 24?48h,then decreased.This suggests that the number of axons in the basal ganglia region after HIBD first recovered and increased,then decreased,and then increased.Compared with other groups,the low expression of 6?12h group was statistically different(P<0.05).And compared with other groups,the high expression of 24?48h group was statistically different(P<0.05).Conclusions:(1)We found that HIBD can affect the expression of Syn and Neu in brain tissues,which can change in a short time.(2)The neural network reconstruction process after HIBD is relatively active.The brain tissue in the developmental stage has a strong neuroplasticity,and the brain nerve after HIBD has a strong self-repair ability.(3)Syn and Neu play a joint role in the nerve regeneration process after HIBD to ensure the correct neural network reconstruction process.