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Objective: rat brain hydraulic shock early after injury, seizures model, observed crackdown behavioral changes and abnormal EEG; combined with the expression of glial fibrillary acidic protein in the hippocampus and hippocampal mossy fibers change, explore trauma early after the onset of epilepsy mechanism. Method: 1. Rat brain Hydraulic shock injury caused by the animal model of early seizures 50 SD rats, male or female, weight 300g-350g, were randomly divided into: (1) blank control group of 10, do not give any treatment. (2) control group (sham operation group) 10, to give the same anesthesia and surgery of the experimental rats, but does not give the blow. (3) surgery group (n = 30), according to the crackdown (0.1kPa, 0.2kPa, 0.3kPa) is divided into three sub-groups, each sub-group (n = 10). 10% chloral hydrate anesthesia, the longitudinal cut the craniotomy top skin in the left parietal bone (from the sagittal suture, coronal suture 5mm) at the dental grinding drill to remove bone window with a diameter of 5 mm, to maintain the integrity of the dura mater, fluid percussion device against tube fixed in the bone window, poly zinc carboxylate cements stationary seal the connection. Animal stereotactic rats were fixed, awareness components to be rats regained consciousness, the adjustment caused by the strike force were 0.1kPa, 0.2kPa, 0.3kPa, induced by light, moderate and severe brain damage. Suture wounds, after rats were fed ad libitum water, can not eat in water to give a nasogastric feeding the surgery our 7-day killed. (2) after injury behavior observations and EEG monitoring after injury behavioral observation: observed intensity blast injury in rats after seizures, extent, seizures severity of the judgment based on the Racine score improved over the standard: 0 without any detection to clinical signs of EEG epilepsy: I Class mouth facial spasm, nodding; II-class side of the forelimb convulsive fits; class III the bilateral forelimb cramps; 4 forelimb clonic the tonic; V level forelimb clonic, tonic and relaxation. Epilepsy bisector 0-II level is considered to be local, Ratings III-V level is considered to be secondary generalized epilepsy. Throughout the monitoring phase 2 or more than 2 times epilepsy animal is considered to have seizures. At the same time hurt EEG monitoring three days, the injured side of the brain measuring electrode laying fixed: cortical shallow electrode position of the anterior fontanelle after 1.0mm, 2.0mm lateral to the midline; hippocampal electrode: the anterior fontanelle 3.8mm, 2.0mm lateral to the midline deep 3.4mm. 3 days after injury EEG monitoring. The sharp waves, spikes, sharp (spine) slow wave complex identified as epilepsy. (3) changes in rat hippocampus area 3.1 hippocampal region pathological changes randomly each sub-group of five rats killed 7 days after injury, the left ventricle - ascending aorta intubation, rapid infusion of normal saline 150ml, 4% more than POM 300ml (4 ° C, 0.1 M PBS preparation, pH 7.4) to slow down after 2h perfusion with 4% paraformaldehyde fixed more than 24 hours, the brain, the hippocampus to both sides of consecutive coronal slices, slice 5μm thick, a slice conventional dehydration, transparent, wax dipped, do hematoxylin - eosin (HE) staining. The control group in the same way the brain, HE staining. 3.2 hippocampal region GFAP detect each slice dewaxed to water, streptomycin avidin - peroxidase (SP) immunohistochemical staining kit for GFAP staining, microscopy, the images collected. 3.3 hippocampal mossy fiber Timm staining the three subgroups modeling after 15 rats in one week were killed after anesthesia, rapid thoracotomy in the left ventricle - the thoracic aorta intubation, rapid infusion of 0.4% sodium sulfide 50ml 4 ° C 4% paraformaldehyde 300ml soon after the first slow infusion for 1 hour or more, 0.4% sodium sulfide 150ml (7min), the brain, fixed in 4% paraformaldehyde for 30 min-1h. Then remove soaked overnight in 30% sucrose sink to the bottom, remove the consecutive coronal sections in a cryostat machine, thickness 30. According Danscher improved method for dyeing, at darkroom into the prepared Timm staining solution by adding 0.5 ml of 17% silver nitrate, the water bath tank was incubated at room temperature for 1.5 hours, water washing, dehydration, transparent sealing microscopic observation images collected and analyzed statistically. Control group the same way Timm staining. Results: 1 of Behaviors seizure frequency and intensity increase with the increase of the crackdown. Mild (0.1 kPa) to combat trauma group there was no seizure behavior, only after injury, arched back, shaking, such as performance. Moderate (0.2kPa) blast injury after only three partial seizures. Severe (0.3kPa) combat injuries early seizures in rats systemic attack 7, the performance of the limb or body paroxysmal seizure, severe cases, seizures or generalized tonic - clonic seizures; 3 partial seizures, behavioral manifestations of stereotypical kind of nodded, chewing, facial tics and other behavior attack. 2 EEG control rats EEG showed the basis of wave alpha waves and beta waves rhythm. Three sub-groups of the experimental group after injury have a short inhibitory low voltage, disappeared within 1.5 hours. Mild insult group is not observed epileptiform EEG waveform; moderate to combat trauma group measured after 120 ± 25 min after injury; the epileptic brain waves severe blow after injury, approximately 90 ± measured after 45 min, epileptic brain electroretinogram waveform performance for high amplitude sharp peaks and a short burst of tall spikes, spikes, sharp slow wave (spine). 3 3.1 hippocampus pathological changes after injury, changes in the hippocampus, in the light microscope hippocampus HE staining: control group hippocampal CA3 number of nerve cells, morphology and distribution were normal. Hydraulic Impact Group: 7 days to combat hippocampus damage the central area of ??injury visible loose tissue, nerve cells deformed stained cells surrounding vacuolar degeneration, nuclear condensation visible, glial cell hypertrophy. Severe combat trauma group. 3.2 glial cells in the hippocampus of GFAP determination of the control group and sham-operated rats of GFAP integrated optical density determination, statistical analysis no significant difference (P GT; 0.05), GFAP-positive cells, sporadic expression of the cell body is not obvious dendritic fine, light staining. Experimental group three sub-groups and the control group, there were significant differences (P lt; 0.05) of GFAP immunohistochemistry enhanced, increasing the cell body, the cell processes become more thickening, increased branch. Severe combat injury hippocampus compared with the other groups, there were significant differences (P lt; 0.05). 3.3 hippocampal mossy fiber Timm staining experiments hippocampus Timm staining in the light microscope observation mossy fiber sprouting. Control rats dentate gyrus and CA3 regions of the hippocampus layers of clear, early seizures group (severe combat trauma group) in hippocampal dentate gyrus layers uneven coloring, coloring deep, showing in the dentate gyrus with the molecular layer and granule cells uppermost continuous, the stain ribbon Timm s staining particles. Conclusion: 1 rat hydraulic brain blast injury model of early seizures, were able to simulate the clinical features of early seizures after human traumatic brain injury, a disease similar to human physiological changes, has good stability and Copy the. 2 degree of early seizures and brain injury are closely related to the frequency of seizures was significantly increased with the increase of the degree of injury. 2 head injury early hippocampal region that is a significant increase in GFAP expression. Early traumatic brain injury within the hippocampus that mossy fiber sprouting hyperplasia increased significantly, and is closely related to the seizures sensitivity.
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