Establishment Of The Model For Brain Injury In Awake Rats And Studies On The DM Of Cerebral Cells After Brain Injury

With the advancement of medication and science and technology, the mortality and morbidity of severe brain injury have decreased quite obviously by modern treatment. In this experiment, we studied the model in rat. Our study aimed to the brain injury models in unanaesthetized and awake rats(BIMuar), and then more study about the brain edema after striking were conducted. This studied is divided two parts:PART I Establishment of the model for brain injury in awake ratsWithout anaesthetinal effect, brain injury models in awake animals (BIMaa) is a ideal method for study of brain injury. BIMaa can be dividedinto two classes: unanaesthetized BIMaa (BIMuaa) and postanaesthetized BIMaa (BIMpaa). BIMuaa do not need unanaesthetine, so the experimental animals usually are fixed by your hand in order to meet the require of the experiment. BIMpaa need to be anaesthetized and/or operated in order to locate exactly and to fix animal firmly[4>12]. After coming out the animals are injured immediately or after a long time. With a striking model of the rat's head, which was designed and made by ourselves, the designated parietal positions of unanaesthetized and awake rats' head was stroked accurately. The striking height can be regulated easily. This model was assessed from dynamics, behavior and pathology. Result: (D Mechanical parameters (calculated by 12cm in height.) : The average linear acceleration and linear velocity prior to striking rat were 250 m/s2 and 7.75 m/s respectively , and striking time was 2.6ms; the average linear acceleration during striking rat was 50 m/s. d> Behavioral and pathological observations showed that in the post-stroked rats.83.3% possessed the typical characteristics of diffuse brain contusion, 2.1%did not so, and 14.58% died. Conclusion: This model can produce BIMuar, and is adapt to models-producing of brain injury in other moderate-to-small animals only by changing some of its parts.PART n Studies on the DM of cerebral cefls after brain injuryThe rats were divided into groups according to the experimental requirement in order to make BIMuaa and the model of treatment using magnesium suLfate. After injured the animal were decapitate the rats' brains were removed for making sections. On the basis of BIMuaa(simulating theclinical brain injury), we probed the main cell which plays a important part in the development of brain edema through analysis of digital morphology of main cerebral cells. 1 .After brain injury the two kinds of cells in the brain change their volume by various proportion. During the early time the neurocyte change its volume obviously, while lately so dose the neuroglia. This suggests that they have different regulation of time and space in the development of brain edema because of their different structure, different metabolism and different cell function. 2. Mg2+ has different effect on different brain cells after head injury. Early Mg*+ impacts mainly on rieurocytes, lately mainly on neuroglia. Conclusion: Mg2* can reduce brain edema, but during different time, it has various target-cells and effect of treatment.