Culture of Motor Neurons from Newborn Rat Spinal Cord

A protocol for the isolation, purification and culture of motor neurons from newborn rat spinal cord was described and the effect of glial cell line-derived neurotrophic factor （GDNF） on the growth of neurite of motor neurons was investigated in vitro. Spinal motor neurons （SMNs） were dissociated from ventral spinal cord of postnatal day 1 rats. The culture system for SMNs was established by density gradient centrifugation, differential adhesion, and use of serum-free defined media and addition of exogenous GDNF. After 72-h culture, the cells displayed the characteristic morphology of motor neurons, exhibited extensive neuritic processes and were positive for choline acetyl- transferase （CHAT） expression. The neurite length of SMNs in GDNF groups was significantly longer than that in control group （P〈0.05）. This protocol can be adapted for various postnatal motor neurons studies.

Environmental enrichment promotes neural remodeling in newborn rats with hypoxic-ischemic brain damage

We evaluated the effect of hypoxic-ischemic brain damage and treatment with early environmental enrichment intervention on development of newborn rats, as evaluated by light and electron microscopy and morphometry. Early intervention with environmental enrichment intelligence training attenuated brain edema and neuronal injury, promoted neuronal repair, and increased neuronal plasticity in the frontal lobe cortex of the newborn rats with hypoxic-ischemic brain damage.

Interventional effect of laser acupoint radiation on the expression of Nissl body and brain-derived neurotrophic factor in newborn rat models with ischemic/hypoxic cerebral injury

BACKGROUND： Some researches report that He-Ne laser can activate function of erythrocytes and increase content of blood and oxygen via bio-stimulating effect; therefore, it suspects that laser radiation at Baihui and Dazhui can partially increase blood circulation for oxygen-supplying content of brain and improve functional status of neurons. OBJECTIVE： To verify the effects of laser radiation at Baihui and Dazhui on the expression of Nissl body of brain tissue neurons and brain-derived neurotrophic factor （BDNF） in newborn rats with ischemic/hypoxic cerebral injury. DESIGN： Randomized controlled animal study. SETTING： Department of Neurological Histochemistry, Xianning University. MATERIALS： Forty Wistar rats of 7 - 8 days old, weighing 15 - 20 g and of both genders, were selected from Wuhan Experimental Animal Center. All the rats were randomly divided into sham operation group （n =8）, model group （n =16） and radiation group （n = 16）. The experimental animals were disposed according to ethical criteria. BDNF kit was provided by Wuhan Boster Bioengineering Co., Ltd. METHODS： The experiment was carried out in the Department of Neurological Histochemistry, Xianning University from April 2005 to October 2006. Rats in the radiation group and model group were performed with ligation of left common carotid artery, recovered at room temperature for 1 - 6 days, maintained in self-made hypoxic cabin under normal pressure and injected mixture gas （0.05 volume fraction of 02 and 0.92 volume fraction of N2） for 2 hours. In addition, rats in the sham operation group were treated with separation of left common carotid artery but not ligation and hypoxia. Rats in the model group were not given any treatment; while, rats in the radiation group were exposed with He-Ne laser of 63.28 nm in the wave length at Baihui and Dazhui acupoints on the second day after ischemia-hypoxia. The radiation was given for 10 minutes per day and once a day. Ten days were regarded as a course and the rats were exposed for 2 courses in total. At 20 days after routine breeding, left hemisphere tissues of rats in the three groups were collected for staining of Nissl body and immunohistochemistry of BDNF. MAIN OUTCOME MEASURES： Nissl body staining in left hemisphere tissue and expression of immune positive cells of BDNF. RESULTS： All 40 rats were involved in the final analysis. （1） Nissl body staining： Neuronal cytoplasm of brain tissue was full of blue granule Nissl bodies in the sham operation group; while, Nissl body in neuronal cytoplasm in the model group was stained slightly and had a certain degree of degeneration; meanwhile, there were a lot of blank area in ischemic region. Nissl body in neuron cytoplasm was gradually recovered in the radiation group and relieved as compared with that in the model group. （2） Positive cells of BDNF： Number of immune positive cells of BDNF which were ligated in lateral cerebral hemisphere of rats in the model group was higher than that in the sham operation group （P 〈 0.05）; while, BDNF expression in the radiation group was increased as compared with that in the model group （P 〈 0.05）. CONCLUSION： After laser acupoint radiation, Nissl body is increased and BDNF expression is also increased. This suggests that laser acupoint radiation has neuroprotective effect on brain tissue after ischemia-hypoxia injury.

Effect of Retinoic acid on Platelet-derived Growth Factorand Lung Development in Newborn Rats

Summary: The influence of platelet-derived growth factor (PDGF) on lung development in newborn rats and the effect of retinoic acid (RA) on PDGF in lung development were investigated. Newborn Sprague-Dawley (SD) rats were randomly assigned to two groups: control group and RA group. The rats in RA group was intraperitoneally injected with all trans-retinoic acid (500 μg/kg every day) for consecutive 3 days after birth, while those in the control group were not subjected to intervention. Immunohistochemical assay was performed to locate the expression of PDGF. mRNA levels of PDGF were measured by reverse transcription polymerase chain reaction (RT-PCR) at age of 1, 3, 5, 7, 10, 14, 21 days. The method of radial alveolar counts (RAC) was used to measure the amount of the alveoli of the lungs. It was found that with increasing days, levels of PDGF-A and PDGF-B changed to verying degrees. RA could elevate significantly the expression levels of PDGF-A mRNA and protein (P<0.01), but not affect the expression levels of PDGF-B mRNA and protein markedly (P>0.05). It is suggested that PDGF might play an important role in lung development. RA can stimulate lung development through increasing the expression levels of PDGF-A mRNA and protein.

Changes in hippocampal neurons and memory function during the developmental stage of newborn rats with hypoxic-ischemic encephalopathy

BACKGROUND: Under the normal circumstance, there exist some synapses with inactive functions in central nervous system (CNS), but these functions are activated following nerve injury. At the early stage of brain injury, the abnormal functions of brain are varied, and they have very strong plasticity and are corrected easily. OBJECTIVE: To observe the changes of neuronal morphology in hippocampal CA1 region and memory function in newborn rats with hypoxic-ischemic encephalopathy(HIE) from ischemia 6 hours to adult. DESIGN: Completely randomized grouping, controlled experiment. SETTING: Taian Health Center for Women and Children; Taishan Medical College. MATERIALS: Altogether 120 seven-day-old Wistar rats, of clean grade, were provided by the Experimental Animal Center, Shandong University of Traditional Chinese Medicine. Synaptophysin (SYN) polyclonal antibody was provided by Maixin Biological Company, Fuzhou. METHODS: This experiment was carried out in the Laboratory of Morphology, Taishan Medical College between October 2000 and December 2003. ① The newborn rats were randomly divided into 2 groups: model group and control group, 60 rats in each group. Five rats were chosen from each group at postoperative 6 hours, 24 hours, 72 hours, 7 days, 2 weeks and 3 weeks separately for immunohistochemical staining. Fifteen newborn rats were chosen from each group at postoperative 4 weeks and 2 months separately for testing memory ability (After test, 5 rats from each group were sacrificed and used for immunohistochemical staining)② The right common carotid artery of newborn rats of model group was ligated under the anesthetized status. After two hours of incubation, the rats were placed for 2 hours in a container filled with nitrogen oxygen atmosphere containing 0.08 volume fraction of oxygen, thus, HIE models were created; As for the newborn rats in the control group, only blood vessels were isolated, and they were not ligated and hypoxia-treated. ③ Thalamencephal tissue sections of newborn rats of two groups were performed DAB developing and haematoxylin slight staining. Cells with normal nucleous in 250 μm-long granular layer which started from hippocampal CA1 region were counted with image analysis system under high-fold optical microscope (×600), and the thickness of granular layer was measured. The absorbance (A) of positive reactant of SYN in immunohistochemically-stained CA1 region was measured. Learning and memory ability were measured with step through test 3 times successively. ④ t test and paired t test were used for comparing intergroup and intragroup difference of measurement data respectively, and Chi-square for comparing the difference of enumeration data. MAIN OUTCOME MEASURES: Comparison of cytological changes in hippocampal CA1 region and memory ability at different postoperative time points between two groups. RESULTS: Totally 120 newborn rats were involved in the result analysis. ① Cell morphological changes in hippocampal CA1 region: In the control group, with aging, perikaryon, nucleus and nucleolus in cortex of parietal lobe were significantly increased, Nissl body was compacted, the amount of neurons was declined, but the A of SYN positive reactant was relatively increased. In the model group, at postoperative each time point, neurons were seriously shrunk and dark-stained, nucleus was contracted, chromatin was condensed, nucleolus was unclear, even cells disappeared, especially the cells in 6 hours and 24 hours groups. The amount of neurons with normal morphology in hippocampal CA1 region and granular layer thickness in the model group at postoperative each time point were significantly less or smaller than those in the control group at postoperative 6 hours respectively (t =3.002-1.254, P < 0.01). The A value of SYN positive reactant at postoperative 2, 3 and 4 weeks was significantly higher than that at previous time point (t =2.011-2.716,P < 0.05-0.01). ② Test results of learning and memory ability: In the first test, there was no significant difference in the ratio of rats which kept memory ability between two groups (P > 0.05); In the third test, the ratio of rats which kept memory ability in the model group was significantly lower than that in the control group at postoperative 4 weeks and 2 months[53%(8/15),100%(15/15);60%(9/15),93%(14/15),χ 2=2.863,2.901,P < 0.01]. CONCLUSION: The destroyed hippocampal structure induces the decrease of learning and memory ability of developmental rats. Early interference can increase the quality of neurons and also promote functional development of the nervous system.

Nerve protective effect of Baicalin on newborn HIBD rats

Objetive:To investigate the nerve protective effect and mechanism of baicalin on newborn rats with hypoxic ischemic brain damage(HIBD).Methods:A total of 64 SD newborn rats were randomlu divided into control group.model group.nerve growth factor group and baicalin group.with 16 in each group.Left carotid artery ligation method was adopted to establish the HIBD model except fou in control group,which was treatde with intraperitoneal injection of salin e10mL/kg for 3 d.After oxygen recovery on hypoxia ischemia rats.intraperitoneal injectionof salin 10mL/kg was adopted in model group for 3 d.Intraperitoneal injection of nerve growth factor injection50μg/kg per day was adopted in nerve growth factor group for 3 d:intraperitoneal injection of radix scutellariae 16mg/kg per day was adopted in baicalin group for 3 d after modeeling.Four rats of each group were sacrificed at Day 1,2,3,7 for microscopic observation of pathological morphological changes in brain tissus aften HE staining,S-P immunohistochemical method was used for observation of Fas and FasL expression in brain cells.Results:Neat structure of cells was observed in control group;edema cells in disordered arrangement was observed in model group,with some cells necrosis and cavity change;tissue injury in nerve growth factor group and baicalin group was significantly lighter than that in model group;Fas and FasL expression in model group,nerve growth factor group and baicalin group were significantiy higher than that in control group at different time points(P<0.05):Fas and FasL expression in nerve growth factor group and baicalin group were significantly lower than that in model group at different time points(P<0.05):There was no statistical diggerence of Fas,FasL expression at each time point between nerve growth factor group and baicalin group(P>0.05).Conclusions:Baicalin can reduce expression of Fas and FasL in HIBD rats,inhibit apoptosis of nerve cells,thus achieve the protective effect on HIBD rat nerves.

Role of neuronal nitric oxide synthase and inducible nitric oxide synthase in intestinal injury in neonatal rats

瞄准：与肠的损害在新生的老鼠调查神经元的氮的氧化物 synthase ( nNOS )和可诱导的氮的氧化物 synthase ( i NOS )的动态变化和角色并且定义引起坏死小肠结肠炎( NEC )是否在粘膜与氮的氧化物 synthase ( NOS )的层次被联系影响的肠织物。方法：Wistar 老鼠在年龄的不到 24 h 与 5 mg/kg 收到了腹膜内注射脂肪的多糖(LPS ) 。回肠纸巾为 NEC 的组织学的评估并且为 nNOS 和 i NOS 的大小在 1， 3， 6， 12 和 24 h 追随者 LPS 挑战被收集。在肠的损害的度和 NOS 的层次之间的关联是坚定的。结果：注射 LPS 的小狗在损害分数对控制显示出重要增加。nNOS 蛋白质和 mRNA 的表示在 LPS 注射以后被减少。在 nNOS 蛋白质和在 24 h 以内的中部的肠的损害的等级之间有否定重要关联。i NOS 蛋白质和 mRNA 的表示显著地在肠的损害的山峰被增加。结论：nNOS 和 i NOS 在导致 LPS 的肠的损害起不同作用。小心应该在 NEC 有关 NOS 禁止者的潜在的治疗学的使用被施加。

Dynamic change of epidermal growth factor in neonatal rat with intestine injury

AIM: To determine whether diminished levels of epidermal growth factor (EGF) were present in neo-natal rats with intestinal injury and related with the degree of intestinal injury, so we modeled a model in neo-natal rats of intestinal injury and to examine the dynamic levels of EGF on injury of intestine.METHODS: One-day-old Wistar rat pups received an intraperitoneally injection with 4 mg/kg lipopolysaccharide (LPS), followed by collection of ileum tissue at 1, 3, 6, 12,and 24 h following LPS administration. The ileum was for histological evaluation of NEC and for measurements of EGF using ABC-ELISA. The correlation between the degree of intestinal injury and levels of EGF was determined. RESULTS: The LPS-injected pups also showed a significant increase in injury scores at 1, 3, 6, 12, and 24 h [respectively, (1.08±0.61), (1.63±0.84), (1.95±0.72), (2.42±0.43)and (2.21±0.53)] vsthe control (0.12±0.17) (P＜0.01).EGF levels at 1, 3, 6, 12 h [respectively, (245.6±49.0), (221.4±39.0), (223.4±48.1), (246.0±46.6)] pg/mg were significantly loss than the control (275.6±50.4) pg/mg (P＜0.05). There was a significant negative correlation between the EGF levels and the grade of intestinal injury within 24 h (P＜0.05).CONCLUSION: Neo-natal rats with intestinal injury have significantly lower levels of ileum EGF. Reduced levels of this growth factor might be related to the pathogenesis of NEC.

Development of the Gusto Facial Reflex in Perinatally Undernourished Rats

In the rat, the taste system plays a critical role in motivating the animal to consume nutrients and avoid toxic substances. In neonatal rat the orofacial movements can be modified by the application of sucrose and quinine in the mouth, producing ingestion or rejection responses, respectively, but there is no information available on the gusto facial reflexes (GFR) under perinatal fasting. The aim of the present study was to determine how undernutrition can affect the development of orofacial responses to sucrose, quinine, and NaCl during early development. Pregnant dams were undernourished by being given 50% of a balanced diet from G6 to G12, 60% from G13-G18, and 100% from G19-G21. On postpartum days 0 - 9, prenatally underfed (UG) pups continued the undernourishment by remaining for 12 h with a foster dam and 12 h with a nipple-ligated mother. Stimuli were presented as a single droplet of sucrose (S), sodium chloride (NaCl), quinine hydrochloride (Q), and water (W) onto the lips at 1, 3, 5, 7, and 9 days of age, and mouth-opening frequency (MO) and lip-licking frequency (LL) were analyzed. The results show consistent effects associated with age, but not with diet, except in the cases of 0.01 M Q, which provoked in the UG subjects increased MO and the reduction of LL, and 0.1 M Q, which consistently reduced both responses. Moreover, S provoked increases in both MO and LL at 0.1 M while NaCl and water elicited minimal effects on GFR. These data suggest that perinatal undernutrition affects the basic components of the gustatory system necessary to produce GFR in the first postnatal days by possibly interfering with the integration of taste input for food learning and the hedonic aspects of gustatory cues.

Selecting representative ages for developmental changes of respiratory irregularities and hypoxic ventilatory response in rats

Apnea frequency and the weak ventilatory response to hypoxia are a major clinical correlates of the immaturity of respiratory control system in preterm neonates. Rats are frequently used as model to study the respiratory control during development. However, little is known about the postnatal ages that best represent these respiratory irregularities and the hypoxic ventilatory response. Using plethysmography, we assessed baseline minute ventilation, ventilatory response to moderate hypoxia (FiO2 = 12%, 20 min) and apnea frequency in awake and non-anesthetized rats at the postnatal ages of 1, 4, 7, 12, 21 and 90 days old (P1, P4, P7, P12, P21, and P90, respectively). Baseline minute ventilation slightly increased in P4 (~25% vs P1) then gradually decreased with age (age effect: p < 0.05). The lowest level of ventilation was observed in P90 (p < 0.01 vs all ages). Minute ventilation (% from baseline) in response to hypoxia showed the well-known biphasic pattern in all rats at 12 days old or less. Minute ventilation at the initial phase of the hypoxic response was not significantly different between P1, P4, between P7, P12 and between P21, P90. The late phase of the hypoxic response was similar between P1, P4, and between P21, P90, but was significantly different between P7 and P12 (p < 0.05). Under baseline or hypoxic condition, the higher number of apnea frequency (spontaneous and post- sigh) was observed in P1, it then decreased progressively with age (age effect: p < 0.01 for baseline;p < 0.001 for hypoxia). These results suggest that when P4, P7 and P12 are selected to represent the age-dependent changes of the hypoxic ventilatory response in rats, the P1 rats should be included to better describe the age-dependence of apnea frequency.

Protective effect of insulin and glucose at different concentrations on penicillin-induced astrocyte death on the primer astroglial cell line

Astrocytes perform many functions in the brain and spinal cord.Glucose metabolism is important for astroglial cells and astrocytes are the only cells with insulin receptors in the brain.The common antibiotic penicillin is also a chemical agent that causes degenerative effect on neuronal cell.The aim of this study is to show the effect of insulin and glucose at different concentrations on the astrocyte death induced by penicillin on primer astroglial cell line.It is well known that intracranial penicillin treatment causes neuronal cell death and it is used for experimental epilepsy model commonly.Previous studies showed that insulin and glucose might protect neuronal cell in case of proper concentrations.But,the present study is about the effect of insulin and glucose against astrocyte death induced by penicillin.For this purpose,newborn rat brain was extracted and then mechanically dissociated to astroglial cell suspension and finally grown in culture medium.Clutters were maintained for 2 weeks prior to being used in these experiments.Different concentrations of insulin（0,1,3 nM）and glucose（0,3,30 mM）were used in media without penicillin and with 2 500μM penicillin.Penicillin decreased the viability of astroglial cell seriously.The highest cell viability appeared in medium with 3 nM insulin and 3 mM glucose but without penicillin.However,in medium with penicillin,the best cell survival was in medium with 1 nM insulin but without glucose. We concluded that insulin and glucose show protective effects on the damage induced by penicillin to primer astroglial cell line.Interestingly,cell survival depends on concentrations of insulin and glucose strongly.The results of this study will help to explain cerebrovascular pathologies parallel to insulin and glucose conditions of patient after intracranial injuries.

新生乳鼠肠道铁过载模型的建立

目的通过灌喂硫酸亚铁·七水化合物(FeSO_(4)·7H_(2)O)建立新生乳鼠肠道铁过载模型,并探讨适宜的建模铁浓度。方法将30只新生的乳鼠随机分为对照组、A组、B组、C组、D组(每组6只),于乳鼠出生后第2~7天分别给予灌喂0 mg/kg、10 mg/kg、50 mg/kg、100 mg/kg、300 mg/kg的FeSO_(4)·7H_(2)O溶液,记录干预期间乳鼠的体重变化。于出生后第8天处死各组乳鼠,取回肠组织,进行HE染色、普鲁士蓝染色观察各组乳鼠回肠组织的病理变化及铁沉积情况,检测各组乳鼠回肠组织的总铁含量及铁蛋白重链1(FTH1)蛋白表达水平。结果(1)各组乳鼠的体重均呈增长的趋势(均P<0.05);出生后第3天,B组和D组乳鼠体重低于对照组,且D组乳鼠体重低于A组和C组(均P<0.05);出生后第7天,D组乳鼠的体重仍低于对照组、A组、C组(均P<0.05),而A组、B组和C组的乳鼠体重与对照组乳鼠体重比较差异均无统计学意义(均P>0.05)。(2)与对照组相比,各模型组乳鼠回肠组织均出现Gruenhagen's间隙,均存在不同程度的病理损害及铁沉积,且C组和D组乳鼠回肠组织的总铁含量均增加(均P<0.05),其中C组乳鼠上述现象最为明显。(3)B组、C组和D组回肠组织的FTH1蛋白表达水平均高于对照组(均P<0.05)。结论灌喂FeSO_(4)·7H_(2)O溶液可以建立新生乳鼠肠道铁过载模型。每天灌喂100 mg/kg的FeSO_(4)·7H_(2)O溶液(铁浓度为20 mg/kg)可在短时间内造成新生乳鼠肠道出现较为明显的铁沉积,但不会明显影响乳鼠的肠道吸收功能及体重增长。

神经再生素对新生大鼠脊髓细胞凋亡的影响

目的 :观察神经再生素对新生大鼠脊髓细胞凋亡的影响。方法 :将新生 SD大鼠一侧坐骨神经切断后 ,用无菌止血海绵包裹断离的神经近侧端 ,海绵内加入神经再生素 ,术后 3、6、1 2 h用 TUNEL法在光镜下检测 L4 -L5脊髓细胞凋亡情况 ,分别以神经生长因子和生理盐水作为阳性和阴性对照。结果 :新生大鼠在坐骨神经切断后脊髓细胞出现大量凋亡 ,神经再生素组凋亡细胞数量较生理盐水组显著减少 ( P<0 .0 1 ) ;神经再生素组与神经生长因子组之间凋亡细胞数量的差别无显著性意义 ( P>0 .0 5 )。结论

新生大鼠海马神经元原代无血清培养与鉴定

目的建立一种简单、易行的海马神经元无血清体外培养方法以获得高纯度、高活力的海马神经元。方法取新生24 h内SD大鼠,分离海马,经消化后种植于包被有Matrigel基膜的玻片上,24 h后换含有N2、B27的Neuro-basal无血清培养基,于不同时间在倒置相差显微镜下观察细胞的生长状态;采用β-tublinⅢ免疫荧光细胞化学技术鉴定海马神经元纯度。结果大部分海马神经元于3～24 h贴壁且可长出细长突起,3 d细胞具有典型神经元的形态特征,5d后神经元突起进一步增多并形成稠密的网络连接,7 d后神经元胞体丰满,趋于成熟。经β-tublinШ免疫荧光技术鉴定纯度为94.2%±3.6%。结论此方法简单有效,可获得高纯度的海马神经元。

丹参防治新生大鼠缺氧缺血性脑病长期疗效观察

缺氧前、后分别给７日龄Ｗｉｓｔａｒ新生大鼠ＨＩＥ模型腹腔注射丹参注射液，４周后处死。结果显示：预防组用药效果显著，能使脑萎缩、软化、液化等形态学病变发生率由对照组的９２．３１％降到３８．０１％（Ｐ＜０．０５），脑萎缩程度明显减轻（Ｐ＜０．００１），眼和／或视神经萎缩发生率由１００％降到６６．６７％（Ｐ＜０．０５），治疗也能明显减轻脑萎缩程度（Ｐ＜０．０５）。

新生大鼠反复惊厥对脑内γ-氨基丁酸A受体α1和γ2亚单位表达的长期影响

目的：研究新生期反复惊厥对大鼠脑内γ-氨基丁酸（γ-aminobutyric acid，GABA）A受体α1和γ2亚单位表达的长期影响，及成年期记忆功能和惊厥阈的长期改变。方法：将生后7天（postnatal 7d，P7）的SD大鼠随机分成两组，每组16只，惊厥组每日吸入三氟乙醚诱导惊厥发作1次，每次持续30min，连续6d；对照组同样操作但不吸入三氟乙醚。两组大鼠于出生后第61～65天（P61～P65）行Morris水迷宫实验，于P75时给予大鼠腹腔注射戊四唑测定大鼠的惊厥阈。随即处死大鼠，分别采用免疫组化方法和RT-PCR方法观察大鼠大脑皮层及海马GABAA受体（GABAAR）α1和γ2亚单位表达的变化。结果：惊厥组大鼠在P64的寻找水下平台时间[（82424±35622）ms]较对照组[（40712±29467）ms]明显延长（P=0．001）。在P65，惊厥组大鼠120s内穿越原平台位置次数[（1．2±0．9）次]较对照组[（3．1±1．3）次]明显减少（P〈0．001）。惊厥组大鼠注射戊四唑后发生惊厥的潜伏期[（1487±662）s]与对照组[（1841±648）s]比较差异无统计学意义（P=0．137）。惊厥组大鼠GABAARα1亚单位免疫化学累积光密度在顶叶及海马CA1、CA2和CA4区较对照组明显降低（P〈0．05）；惊厥组大鼠GABA。R12亚单位免疫化学累积光密度在额叶和海马CA4区较对照组明显降低（P〈0．05）。惊厥组大鼠大脑皮层GABAARγ2亚单位和海马区α1亚单位mRNA的表达较对照组明显减少（P〈0．05）。结论：新生大鼠反复惊厥可造成脑内GABA。Rα1和γ2亚单位表达的长期改变，这种改变可能与新生期反复惊厥导致的成年期记忆障碍相关。

神经节苷脂GM1对缺血缺氧后谷氨酸及其转运体神经元的作用

目的 :探讨神经节苷脂GM1对新生大鼠缺氧缺血性脑病保护作用及其可能的机理。方法 :通过建立新生鼠缺氧缺血性脑病动物模型 ,应用免疫组化方法 ,观察缺血缺氧后不同时期脑组织中谷氨酸及其转运体阳性神经元的动态变化 ,以及GM1对其的影响。结果 :缺血缺氧后 6h、1、3d大脑皮层和纹状体中谷氨酸阳性神经元明显减少 ,而谷氨酸转运体阳性神经元有所增加 ,GM1组脑组织损伤明显减轻 ,谷氨酸神经元及谷氨酸转运体神经元较单纯缺氧缺血组明显增多。结论 :神经节苷脂GM1对谷氨酸神经元具有保护作用 。

银杏内酯B对缺氧缺血性脑损伤新生大鼠脑组织Caspase-3及VEGF mRNA表达的影响

目的:观察银杏内酯B(GB)对缺氧缺血性脑损伤(HIBD)新生大鼠脑组织Caspase-3及血管内皮生长因子(VEGF) mRNA表达的影响。方法:清洁级新生7d龄SD大鼠96只,随机分为假手术组、模型组、GB低剂量组及GB高剂量组。后3组采用经典Rice法制作HIBD动物模型,假手术组不行缺氧处理。模型制备4h后GB高、低剂量组分别按10、5mg/kg腹腔注射GB,余2组注射等量生理盐水,1次/d,共5d。造模后第3、7、14和28天每组分别随机选取6只动物处死,荧光定量PCR法检测脑组织Caspase-3及VEGF mRNA的表达。结果:造模后,假手术组各时间点Caspase-3和VEGF mRNA表达水平差异均无统计学意义(F=0.134,0.382,P均>0.05),而模型组、GB低和高剂量组Caspase-3和VEGF mRNA的表达均于造模后第3天达最高,此后逐渐下降,至造模后第28天接近假手术组水平(F=109.356,33.281,9.703和39.945,103.903,60.956,P<0.001)。造模后第3、7和14天,4组Caspase-3和VEGFmRNA表达水平差异均有统计学意义(F=128.865和97.912,40.058和57.121,24.184和8.621,P均<0.001);与假手术组比较,模型组Caspase-3和VEGFmRNA的表达均升高(P<0.05);与模型组比较,GB低和高剂量组Caspase-3的表达降低,VEGF mRNA的表达升高(P<0.05);GB高剂量组2指标的变化较低剂量组更明显(P<0.05)。结论:GB可下调HIBD后脑组织Caspase-3表达及上调VEGF表达,从而减轻并修复脑损伤。

新生大鼠大脑皮层神经细胞的体外原代培养

本文探讨了新生大鼠出生２４ｈ内大脑皮层神经细胞原代培养的方法，建立了稳定的神经细胞培养模型。通过光镜和细胞Ｎｉｓｓｌ染色、ＡＣｈＥ染色，对培养各阶段的神经细胞进行了观察，系统地描述了它们的生长发育过程和形态特征。本方法扩大了大脑皮层神经细胞培养材料的来源。另外，对培养方法的特点进行了讨论。

外源性谷氨酸致新生鼠脑兴奋毒性神经变性的形态学研究

目的 :探讨外源性谷氨酸对新生鼠脑细胞的兴奋毒性作用。方法 :新生 7天SD大鼠 ,背部皮下注射单钠谷氨酸 (MSG) 2mg/ g ,在 2h、6～ 8h、2 4～ 2 8h分别光镜和电镜观察脑细胞的形态改变。结果 :光镜下 ,2h未见明显异常 ,此后可见多处脑细胞肿胀 ,进而细胞固缩。电镜着重观察海马神经元 ,变化一为神经元胞体和树突巨大膨胀 ,伴随着内质网膜的空泡化及线粒体由最早期的浓缩到巨大膨胀 ,轴突基本正常 ,核染色质由簇状集聚于核膜下呈钟面排列到向中央积聚成轮廓不规则的团块 ;变化二为胞浆和胞核均浓缩 ,胞奖中有大小不等的空泡。结论 :外源性谷氨酸能引起未成熟脑细胞的死亡 ,为某些食品添加剂对儿童脑细胞的影响的相关研究提供一定的形态学基础。