| Neonatal hypoxic-ischemic brain damage (HIBD) refers to factors such as perinatal asphyxia with hypoxic-ischemic brain damage, the clinical manifestations appeared on a series of encephalopathy. Children often left with severe cerebral palsy, epilepsy, mental retardation, ataxia and other after-effects, to families and society is a great burden. Therefore, the search for an effective method for improving the prevention and treatment of HIBD newborn survival and reduce disability, improve prenatal and postnatal care, improve the quality of China's population has important significance.Hypoxic-ischemic brain tissue supplied by blood circulation improvement and recovery of neuronal function is closely related to. Vascular endothelial growth factor (VEGF) is a group in recent years, the newly discovered angiogenesis factor, is a specific role in vascular endothelial cells of the multifunctional cytokine, but also angiogenesis and neurotrophic factor, not only to promote new blood vessels, but also to play a direct role in the nerve cells neurotrophic and neuroprotective role.ObjectiveIn recent years, physical therapy methods such as electrical stimulation, functional training, acupuncture, massage in the treatment of cerebral ischemia in the course of the disease more and more attention, while the electrical stimulation of the current treatment of adult diseases, the efficacy of cerebral ischemia has been affirmed, but for HIE the efficacy of recovery at home and abroad rarely reported, but the lack of empirical evidence. In this study, through the production of hypoxic-ischemic brain injury model, given electrical stimulation of the cerebellar fastigial nucleus, using immunohistochemical method to observe the brain in the expression of VEGF and its receptors to explore the protective effect of electrical stimulation on brain mechanisms.Materials and methods1 Groupingnew 7-day-old SD rats were 105 healthy male and female open, weight 12-16g, were randomly divided into A, B groups. Each group was divided into control group, model group, electrical stimulation group, A group of 25, B group of all 10. A group made after they die by 1 day,3 days,7 days,14 days,21 days were randomly divided into five groups, each group 5.2 Rice Law modeling7-day-old healthy newborn SD rats, ether inhalation anesthesia, take the left neck incision, free left common carotid artery ligation with silk suture incision, placed in oxygen tank, continuous filled with gas The eight ninety-two flow 2L/min oxygen-nitrogen gas mixture 2h. The control group, only the left common carotid artery was isolated, non-ligation nor hypoxia. Folder after the end of L is a sign of the success of the system model accordingly included in the experiment.3 Electrical stimulation treatmentElectrical stimulation group 12 h after stimulation treatment began, each 30 minutes of electrical stimulation to stimulate the parts of the ear at the equivalent of human mastoid day 1, electrical stimulation intensity 3.5V, frequency 50HZ, a slight tremor of rat limb is appropriate. The control group and model group, no electrical stimulation therapy, only with the corresponding capture time.4 Specimen collection and preparationA group of three rats in each group,respectively, after Id,3d,7d,14d,21d randomly from each of five rats, application of ether anesthesia, cut the chest, exposing the heart, cut right atrial appendage in order to connect 5 Scalp 20ml syringe needle before left ventricular apical perfusion 9g/L saline 50ml, and then perfusion 40g/L paraformaldehyde solution. Along the neck, decapitation, ophthalmic forceps stripping the skull, breaking away from the integrity of the optic nerve and bulbar brain tissue removed,40g/L paraformaldehyde 24h, the brain along the optic chiasm and median eminence at doing coronal incision, separately coronal slices, for VEGF, VEGFR1, VEGFR2 immunohistochemistry testing, and for taking the part of the pathological slices target detection.5 Index Determination5.1 Brain tissue HE stainingOptical microscope observations.5.2 Brain tissue determination of VEGF, VEGFR1, VEGFR2High-powered light microscope, the hippocampus of rat VEGF and VEGFR1, VEGFR2-positive cells in the expression of the sentence of nuclei stained brown positive expression products. Using Image-pro plus 6.0 software system average optical density measurement slices, each slice randomly selected five horizons, whichever is the average.5.3 Memory testThe Y maze test. In the first 28 days after the operation of the B group of rats in each group maze experiment testing to 10 consecutive tests there are 9 times the right response to meet Institute standards, records of each animal discrimination learning labyrinth to reach the standards required before the test number and the correct response rates. Repeat the experiment after 24 h process.6 Statistical analysisUsing SPSS for windows 13.0 statistical analysis, methods for single-factor analysis of variance was used to compare between the two groups 22 LSD-t test, the data are s said toα=0.05 level for significance tests.Results1 HE stainingControl group, nerve cell morphologically normal, cytoplasm-rich cells arranged in neat rows close, clear nucleus, prominent nucleoli, cytoplasm stained uniform, membrane integrity. Pyramidal cells in hippocampus of model group, degeneration, cell gap increases, disordered, normal neuronal loss, we can see a large number of obvious necrosis and necrosis of the central area showed vacuolar change, reduce the number of nerve cells, cytoplasmic shrinkage, nuclear enrichment deeply stained, nucleolus disappeared, the cytoplasm loose, interstitial edema. Electrical stimulation of nerve cell degeneration and necrosis of less degree of injury significantly reduced hippocampal pyramidal cells and neuronal survival numbers. Most of cell morphology is relatively normal.2 VEGF, VEGFR1, VEGFR2 immunohistochemistryElectrical stimulation at each time point VEGF, VEGFR1, VEGFR2 expression was higher than model group and control group (P<0.05); model group at each time point VEGF, VEGFR1, VEGFR2 expression control group (P<0.05) electrical stimulation group and model group, VEGF expressed in the first 3 days and reached the peak last 14 days and begin to decline to 21 days still expressed, VEGFR1, VEGFR2 expression peaked on day 7, last 14 days and begin to decline to 21 days still expression; the control group at each time point of VEGF, VEGFR1, VEGFR2 expression was no significant difference (P> 0.05)3 Memory testsHIBD group (model group) rats 1st day compliance significantly more than the required response to the number of the control group, the correct response rate was significantly lower than the control group, the first two days retest still similar results, while the electrical stimulation Group 1 day compliance was significantly lower than the number required for response to the model group, the correct response rate was significantly higher than the model group, the groups were significant when compared (P<0.05); in the model group, the first two days was no obvious increase accuracy,1 day, compared with the first P> 0.05, all I see markedly improved (P<0.05)Conclusions1 Electrical stimulation can promote HIBD newborn rat brain tissue VEGF and its receptors VEGFR1, VEGFR2 expression.2 HIBD electrical stimulation can improve memory in neonatal rats and cognitive function.
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