Objective To probe the mechanism of anticonvulsant by melatonin from the angle of neurotransmitter.Methods Rat status epilepticus(SE) model was induced by pilocarpine(PILO).?-aminobutyric acid(GABA) content and glutamin acid decarboxylase(GAD)67 mRNA expression was detected at 6,48,72 h,and 7 d in the hippocampus of post-SE rats.The effect of melatonin on these changes was observed.Results GABA content was significantly lower in the hippocampus than in control(P

It was found that citrated rabbit blood in a test tube could be coagulated within 5 seconds after the addition of isobutyl ?-cyanoacrylate.isoamyl ?-cyanoacrylate and isobutyl ?-cyanoacrylate glycolate in different concentrations respectively.All these monomers exhibited quick and reliable styptic effect on the hemorrhage of the liver,the spleen and the kidneys of rabbits and rats respectively,and their styptic effect was superior to that of most conventional hemostatics.The test for their acute toxicity revealed that they were of quite low toxicity and their dosage for adhesive-hemostatic purpose was about one gram.There was no evident injurious effect on the functions of the kidneys and the liver and the peripheral hemogram in rabbits.The test for subacute toxicity revealed no obvious pathological changes but some imflammatory responses over the site of drug application.

Four hours after the spinal cord of rats was injured,the contents of malondi-aldehyde(MDA)and free fatty acid(FFA)were significantly increased,the activity of xan-thine oxidase(XOD)elevated,the activity of superoxide dismutase(SOD)reduced,and the calcium content significantly increased in the tissues of the injured cord.These facts suggest that there is the generation of calcium-mediated free radicals and lipid peroxidation in the membrane.Intravenous injection of saponins of Panax notoginseng(PNS)in the dosage of 30,90,and 270mg/kg could all inhibit the production of MDA; 270mg/kg could inhibit the release of FFA and the activity of XOD;90mg/kg could significantly decrease the calcium content.These findings indicate that the inhibition of PNS on the calcium influx might be one of the mechanisms of anti-lipid peroxidation in spinal cord injury in rats.

Objective To observe the effects of valproic acid (VPA) on function recovery of injuried spinal cord with transplanted neural stem cell in adult rats. Methods 96 SD rats were divided into 4 groups randomly: the injury group, VPA group，NSCs group and NSCs+VPA group. All rats were hemi-sected at T10 level. The rats in VPA group were injected with VPA 300 mg/kg·d introperitoneally twice a day. Those in NSCs group were transplanted with absorbable gelatin sponge absorbing the identified NSCs. Those in NSCs+VPA group were dealed the same as those in NSCs group, and injected with VPA 300 mg/kg·d introperitoneally twice a day. They were assessed with Basso-Beattie-Bresnahan(BBB) scale and electrophysiology examination in 2nd, 4th and 8th week. The nuclear yellow retrograde tracing and DIL anterograde tracing were performed in 8th week. Results The number of neurons traced with DIL and nuclear yellow of NSCs+VPA group were more than that of other groups. The BBB scores and indexes of electrophysiology examination of NSCs+VPA group improved more than other groups, especially the motor evoked potentials. Conclusion VPA promotes neural stem cells transplant to repair the function of injuried spinal cord in adlut rats.

Objective To investigate the effects of essential fatty acids(EFA)on the contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the brain tissues of rats. Methods A total of 30 neonatal rats, 1 month old, were randomly divided into normal, EFA deficiency and fish oil supplement groups and given different feeding stuff for 3 months respectively. The contents of EPA and DHA in brain tissues were determined by high performance liquid chromatography (HPLC). Results As compared with normal group, the contents of EPA and DHA in EFA deficient group were significantly decreased(P

Objective To observe the differentiation of neural stem cells(NSC)into neurons under different astrocytes feeding layers.MethodsThe NSC purified from primary cultured clones and labeled by DAPI in serum-free media were plated in different feeding layers:cyto-plasma astrocytes and fibrous astrocytes respectively with Neural Basal(NB)media.After 10 d,immunohistochemistry with antibody NF-200 was taken to calculate the percents of neurons by 20 fields of vision chosen randomly.The differentiated neurons were stained with AchE and labeled with Fura-3AM.ResultsThe ratios of differentiated neurons in cyto-plasma and fibrous astrocytes were 72% and 43% respectively.In most differentiated neurons the AchE staining was positive and had the activity of Ca2+ stimulated by medicine.ConclusionThe cyto-plasma astrocytes can induced NSC differentiated into neurons,especially into active motor neurons,which can be chosen for a new seeding cells in the nervous tissue engineering.

Objective To explore the expression and change of ski-interacting protein (SKIP) in rats after spinal cord injury. Methods A total of 60 adult female Sprague-Dawley rats were randomly divided into sham group (n=30) and spinal cord injury (SCI) group (n=30), each group was further divided into five time points including one day, three days, five days, seven days, and 14 days with six rats in each time points. The model was established at T10 with modified Allen's technique, and the sham group only bit the lamina of rats. The hindlimbs behavior was assessed with Basso-Beattie-Bresnahan (BBB) score at each time point. The pathological changes of spinal cord neurons were detected with Nissl staining. The expression of SKIP were observed with immunofluorescence staining. Results The BBB scores were signif-icantly lower in each time point in SCI group than in the sham group (t>48.267, P<0.001). Compared with the sham group, Nissl bodies in the cytoplasm of spinal cord neurons began to disintegrate, coalesce and irregularly distribute, the neurons began to degenerate and die on the fifth day, and the damage deteriorated on the 14th day. Immunofluorescence staining showed that SKIP expression was mainly expressed in the gray matter of the spinal cord and little expressed in the white matter. The expression of SKIP gradually increased after SCI, and reached a peak on the fifth day (t=-17.035, P<0.001) and decreased significantly on the 14th day (t=3.853, P<0.05). Conclusion SKIP may be a new signaling molecule, which play an important role in neuronal apoptosis after SCI.

Objective To study the differentiation and proliferation ability of the spinal neural stem cells (NSCs) at different gestational ages in fetal rats. Methods Sprague-Dawley fetal rats were divided into group A (12 days of pregnancy), group B (14 days of pregnancy) and group C (16 days of pregnancy). NSCs were separated with enzyme-assisted microdissection. The diameter and numbers of NSCs balls were measured at different time. The cell growth curve was drawn with CCK8 colorimeter. NSCs were identified with BrdU/Nestin immunohistochemical staining. They were induced with 10% fetal bovine serum for 10 days, and the expression of β-tubulinⅢ and glial fibrillary acidic protein was detected with immunocytochemistry. Results There were cells expressed BrdU, Nestin, β-tubulinⅢ and GFAP in all the group. The most cells (22.74±0.79%) expressed β-tubulinⅢ in the group B, but no significant difference between group B and group C. The cell vitality on the 5th day of third-generation neural stem cells was the most in group B. Conclusion For enzyme-assisted microdissection, it may obtain more neurons to isolate the neural stem cells from 14 days of pregnancy pregnant rats.

Objective To observe the regulative effect of high dose of glucocorticoid (GC) on protein synthesis and mRNA transcription of corticotropin-releasing hormone (CRH) in paraventricular hypothalamic nucleus (PVN) so to ascertain whether there exists difference upon effect of GC either at high dose or at normal dose. Methods A total of 60 Wistar rats were divided into five groups, ie, blank control group, 10 -6 mol/L dexamethasone (DEX) group, 10 -9 mol/L DEX group, 9 g/L saline group and group that was treated with 10 -4 mol/L RU486 first and then with 10 -6 mol/L DEX. The drugs were given through femoral vein. CRH protein expression was measured by means of immunohistochemistry and laser confocal scanning microscophy (LCSM); CRH mRNA transcription level was investigated by in situ hybridization. Results There appeared positive CRH mRNA granules in cytoplasm of PVN after administration with 10 -6 mol/L DEX for 20 minutes but could be seen positive fluorescent granules of CRH protein 30 minutes later, which was reversed at an in advance blockage of GR, as was free in 10 -9 mol/L DEX group, 9 g/L saline group and blank control group. Conclusions High dose of GC can up regulate CRH gene expression in PVN and differs much from the traditional effect of GC at normal dose, as may be due to that high dose of GC exerts effects depending on membrane glucocorticoid receptor but normal dose of GC dose via iGR.

Objective To explore the expression and the changes of ski with time in the injured spinal cord in rats. Methods Sixty adult female Sprague-Dawley rats were randomly divided into sham group (n=30) and injury group (n=30), each group were further divided into 1 week, 2 weeks, 4 weeks, 8 weeks and 12 weeks subgroups, with 6 rats in each subgroup. Spinal cord injury at T10 was established with modi-fied Allen's technique (10 g × 25 mm) in the injury group. The hindlimbs behavior of rats was rated with Basso-Beattie-Bresnahan (BBB) scores 1 day, 3 days, 1 week, 2 weeks, 4 weeks, 8 weeks and 12 weeks after spinal cord injury. Three rats in each subgroup were stained with HE staining to observe the pathological changes of the spinal cord and the formation of cavity. The other 3 rats were analyzed with im-munofluorescence staining of ski and semi quantitative analysis. Results The BBB scores of each time point were less in the injury group than in the sham group (P<0.05). Necrosis was the major pathological change in the injury groups 1 and 2 weeks after injury;cystic cavity completely formed 4 weeks after injury, with dense scar tissue around it;there was no significant change in the cavity and scar 8 and 12 weeks after injury, however, the adjacent spinal cord was obviously thinner. Ski expressed little in the normal spinal cord, and expressed more and more after injury, peaked at 8 weeks and decreased then. Ski was mainly observed in white matter in the sham group and 12 weeks injury subgroup, which was in gray matter 2, 4 and 8 weeks after injury. Ski was highly expressed around the cavity in injury center and formed high expression band. Conclusion Ski expresses after spinal cord injury in rats, that may be associated with the activation and prolif-eration of astrocytes and the formation of glial scar.