The Study About The Effect Of Mild Therapeutic Hypothermia In Different Terms On Adult Neurogenesis After Traumatic Brain Injury

Part?Objective:To investigate the effects of endogenous neurogenesis in cerebral cortex and hippocampus of adult rats after vary levels of traumatic brain injuryMethod:1.SD rats were divided into sham and TBI groups(including mild TBI(miTBI)group,moderate TBI(moTBI)group,severe TBI(sTBI)group),the rats of sham group only open bone windows without any injury,And the traumatic brain injury models of TBI groups prepared by eCCI instrument.2.Hading the head nuclear magnetic examination immediately after TBI.3.SD rats were injected with BrdU intraperitoneally for 5 days to label newborn neural stem cells.4.The expression of BrdU+ neonatal endogenous neural stem cells in the cerebral cortex and hippocampus was detected by immunohistochemistry on the 7th day after TBI.Results:1.The results about the head magnetic resonance imaging showed the edema area of the injured area of SD rats in each group,miTBI group was smaller than moTBI group,moTBI group was smaller than s TBI group,while sham group without edema.2.The results of immunohistochemistry showed that the expression of BrdU+ neural stem cells in cerebral cortex and hippocampus was as follows,sTBI group was more than moTBI group,miTBI group was less than moTBI group,and the injury sides was more than contralateral,and the sham group was almost none.Conclusion:The greater the level of injury to traumatic brain injury in a certain extent,the more the number of newborn neural stem cells in the cerebral cortex and hippocampus is more.It laid a foundation of experiment for clinical study,and provided a suitable TBI model for the next experiment.Part?Objective:To investigate the effects of mild Therapeutic Hypothermia on endogenous neurogenesis in the cerebral cortex and hippocampus of adult rats after severe traumatic brain injury.Method:1.SD rats were divided into sham group and sTBI groups that hereinafter referred to as TBI group(including normal temperature(NT)group,3 hours mild therapeutic hypothermia(3hTH)group,6 hours mild Therapeutic hypothermia(6hTH)group and 10 hours mild Therapeutic hypothermia(10hTH)group).sham group rats only open bone window and without any injury.Rats in the TBI groups were treated with an eCCI instrument to prepare the traumatic brain injury models.And then,the rats in the NT group were placed at room temperature and the hypothermia groups was placed on the ice blanket under anesthesia to maintain the rectal temperature at about 33 � C,giving 3 hours,6 hours and 10 hours of mild Therapeutic hypothermia respectively.2.SD rats were injected with BrdU intraperitoneally for 5 days to mark the newborn neural stem cells.3.The BrdU+/DCX+ newborn immature neonatal neurons,BrdU+/NeuN+ newborn mature neonatal neurons and BrdU+/GFAP+ newborn Astrocytes were detected by immunofluorescence assay,at the 7th day after TBI.4.To compare the scores at 24 hours and 2 months after TBI,use the same batch of rats under the same conditions.Results:1.The number of BrdU+/DCX+ newborn immature neonatal neurons in the cerebral cortex and hippocampus: was the highest in 10 hTH group,the 6hTH group was followed,the 3hTH group was less than 6hTH group,the Sham group was nearly no positive results in the cerebral cortex and Very few in hippocampus,and the differences were statistically significant.2.The number of BrdU+/NeuN+ newborn mature neonatal neurons in the cerebral cortex and hippocampus: was the highest in 10 hTH group,the 6hTH group was followed,the 3hTH group less than 6h TH group,the NT group less than 3hTH group,and the sham group less than NT group in hippocampus and was no positive results in the cerebral cortex,and the differences were statistically significant.3.The number of BrdU+/GFAP+ newborn astrocytes: was the least in sham group,the 10 hTH group was more than sham group,the 6hTH group was more than 10 hTH group,the 3hTH group was more than 6hTH group,and the highest in NT group,and the differences were statistically significant.6.Results of mNSS:The comparation of mNSS scores in the group of the 3hTH group,the 6hTH group or the 10 hTH group,was that was significantly lower at 2 months after TBI than those at 24 hours after TBI,and the difference was statistically significant.mNSS scores of 10 hTH group was lower than those of NT group,and the difference was statistically significant.conclusion:Mild therapeutic hypothermia can promote the occurrence of endogenous neurogenesis after TBI,and the longer the term the more obvious.Mild therapeutic hypothermia can also better promote the recovery of neurological function after TBI,and long-term mild therapy hypothermia is most obvious.