Traumatic Brain Injury In Rats Acetylcholine, Brain Source Sex Researches On The Change Of Nerve Growth Factor Expression

0bjective：To explore the profiles of acetylcholine (Ach)and brain-derived neurotrophicfactor(BDNF) in rat models of traumatic brain injury(TBI).Methods：192 healthy male SD rats (weight 250g～300g)were randomized into theinjury(n=144) and control groups(n=48)．The injury group was further divided randomly into 3secondary groups based on severity of injury(mild，moderate and severe，n=48 eAch)．Theseinjury—graded groups and control group were again stratified into 8sub-groups according totime from TBI(15min，0.5，1，3，6，1 2，24 and 48 h)，such that every sub—group had 6 rats．Tocreate TBI models，the rats assigned to injury group received different powers delivered withreference to FEENEY’S method. Injury groups’rats were respectively given the different power（200g．cm、600g．cm and 1000g.cm）by the equipment of hitting by freely falling，and thenthe rats were made into three types of traumatic brain injury models. Immediately after theinjury and at specific time spots，hippocampus and cortex samples were collected from eAchrat. The brain tissue 1evels of Ach and BDNF were measured with ELISA method．Part ofbrain tissues were also examined by hematoxylin-eosine dyeing method in order to study thehistopathological changes.Results：(1)There was a positive correlation between post—TBI brain tissue 1evels of Achand BDNF（rank correlation coefficient：Hippocampus samples r_s=0.340，P<0.01; cortexsamples r_s=0.311，P<0.01）．The changes in brain tissue Ach featured by a sudden rise aftertrauma，a quick decline that ensued and bellowed the normal level．The changes in brain tissueBDNF featured by a gradual rise after trauma，a gradual decline that ensued．The brain tissuelevels of Ach and BDNF varied significantly across all groups with different severity ofTBI(P<0.01)and time from injury(P<0.01)．(2) Demonstrate by the light microscope: Mild injury group: The focal subarAchnoidhemorrhage and shallow contusion hemorrhagic in cerebral cortex were observed, theneurons with unclear nucleolus and neuronal cell bodies enhanced in eosinophilic stainingaround contusion were visible.The gap between Neurons and neuroglial cell were widened.Moderate injury group: Parietal subarAchnoid hemorrhage were observed. The cerebral corticalcontused . Neuronal around contusion lesions degenerated .Necrotic area increased. Severeinjury group:parietal subarAchnoid hemorrhage, and even subdural hematoma formed. Contusion lesions were seen in the cerebral cortex,even hippocampus, corpus callosum. Thedegeneration of neuronal around contusion lesions and the scope of necrosis further increased.Conclusion：In traumatic brain injury，both brain tissue levels of Ach and BDNF changeregularly to the degree of injury. Detection of brain tissue Ach and BDNF will be helpful toestimate the degree of injury and pathological changes of the traumatic brain injury．...