目的 探讨基于MOOC和移动学习的麻醉解剖学教学效果.方法 选取2017级麻醉学专业学生95名,按照随机分组对照原则将其分两组,其中47名学生采用传统教学方法 实施教学,设为普通组;48名学生采用基于MOOC和移动学习的翻转课堂教学模式实施教学,设为翻转课堂组.采用自主学习能力量表评估学生自主学习能力;并于教学3周后进行阶段性考试.结果 教学3周后,翻转课堂组学生认知能力、综合能力及学习能力评分均显著较普通组高,差异有统计学意义(P<0.05).且翻转课堂组平均成绩明显较普通组高,差异有统计学意义(P<0.05).结论 基于MOOC和移动学习的翻转课堂用于麻醉解剖学教学中能够提高学生自主学习能力,提高学习成绩.

自我评价有利于培养学生的主动学习能力.在医学实验教学中,以实验报告为抓手,引导学生进行自我评价,调动了学生的积极性,激发了学生的实验热情,提高了实验成功率,保证了实验教学质量.

Prolonged exposure to opiates induces a constellation of neuroadaptations, especially in the mesolimbic dopamine system (MLDS), which leads to alteration in the function of motivational circuitry. The neural cell adhesion molecule (NCAM) mediates cell-cell interactions and plays an important role in processes associated with neural plasticity. Moreover, it has been shown that NCAM were related to risk of alcoholism in human populations. Here, coimmunoprecipitation and western blotting were used to investigate whether morphine treatment induced alteration of the expression of NCAM or its signaling level in MLDS. The rats receiving escalating dose of morphine treatment were divided into three groups: morphine 1d, 3d and 5d group, which were injected subcutaneously with morphine hydrochloride for 1 day, 3 days and 5 days, respectively. Twelve hours after the last injection, animals were sacrificed and the tissues of ventral tegmental area (VTA), prefrontal cortex (PFC) and nucleus accumbens (NAc) were punched out to examine the expression of NCAM or its signaling level. The results showed that morphine treatment had no significant effect on the expression of NCAM, but downregulated the phosphorylation of NCAM-associated focal adhesion kinase (FAK) in the VTA and PFC of rats. In the NAc of rats, however, the expression of NCAM and its signaling were not altered significantly by morphine treatment. These results indicated that the downregulation of NCAM signaling in the VTA and PFC might be involved in the formation of morphine addiction.

Necroptosis is characterized by programmed necrotic cell death and autophagic activation and might be involved in the death process of dopaminergic neurons in Parkinson's disease. We hypothesized that necrostatin-1 could block necroptosis and give protection to dopaminergic neurons. There is likely to be crosstalk between necroptosis and other cell death pathways, such as apoptosis and autophagy. PC12 cells were pretreated with necroststin-1 1 hour before exposure to 6-hydroxydopamine. We examined cell viability, mitochondrial membrane potential and expression patterns of apoptotic and necroptotic death signaling proteins. The results showed that the autophagy/lysosomal pathway is involved in the 6-hydroxydopamine-induced death process of PC12 cells. Mitochondrial disability induced overactive autophagy, increased cathepsin B expression, and diminished Bcl-2 expression. Necrostatin-1 within a certain concentration range (5-30 μM) elevated the viability of PC12 cells, stabilized mitochondrial membrane potential, inhibited excessive autophagy, reduced the expression of LC3-II and cathepsin B, and increased Bcl-2 expression. These findings suggest that necrostatin-1 exerted a protective effect against injury on dopaminergic neurons. Necrostatin-1 interacts with the apoptosis signaling pathway during this process. This pathway could be a new neuroprotective and therapeutic target in Parkinson's disease.

Background Cadherins are a group of transmembrane proteins that were originally identified as the cell-surface molecules responsible for Ca2+ dependent cell-cell adhesion.Cadherins play important roles in the regulation of cell adhesion,cell proliferation and cell polarity.Researches have made great progress on cadherins regulating synaptogenesis and synaptic plasticity in recent years.Objective In this article we overview the roles and molecular mechanisms of cdherins in synaptogenesis and synaptic plasticity processes,aims to provide theoretical basis for the treatment of diseases of the nervous system.Content The cadherin overview,the role of cadherin in regulating synaptogenesis and synaptic plasticity and related molecular mechanisms,cadherins and nervous diseases.Trend With the development of research of cadherin in the regulation of synaptogenesis and synaptic plasticity,cadherin will become a new therapeutic target for the treatment of neurological diseases.

Treating neuropathic pain is a major clinical challenge, and several key molecules associated with nociception have been suggested as potential targets for novel analgesics. Many studies have reported the anti-nociceptive effects of glial cell-derived neurotrophic factor (GDNF), but the underlying mechanism remains largely unknown. The present study was performed to assess the effects of GDNF in a mouse model of chronic constriction injury (CCI)-induced neuropathic pain. We also determined the potential role of E-cadherin/p120 catenin (p120ctn) signaling in these effects. Mice received an intrathecal acute injection of PBS, GDNF, and DECMA-1 (an E-cadherin functional blocking antibody) or a combination of DECMA-1 with GDNF on the testing days. Our results demonstrated that CCI caused a rapid decrease in E-cadherin and membrane-associated p120ctn in the spinal dorsal horn. Together, these data demonstrated that E-cadherin-associated p120ctn was upregulated by GDNF and that this upregulation was inhibited by pre-treatment with DECMA-1. Moreover, DECMA-1 significantly inhibited the effect of GDNF on thermal hyperalgesia. These data suggest that GDNF might have a therapeutic potential for the treatment of CCI-induced neuropathic pain and that the E-cadherin/p120ctn might play a role in GDNF-induced attenuation of thermal hyperalgesia.

目的:研究鞘内注射N-乙酰天冬氨酰谷氨酸(N-acetylaspartylglutamate,NAAG)肽酶抑制剂(2-PMPA)对神经病理性疼痛大鼠的镇痛作用及脊髓水平瞬时感受器电位香草酸受体1(TRPV1)表达的影响.方法:取鞘内置管成功的雄性SD大鼠24只,体重200～250 g,随机分为3组(n=8):假手术组(sham组)、坐骨神经慢性压迫性损伤组(CCI组)和2-PMPA治疗组(2-PMPA组).sham组只暴露坐骨神经,但不结扎,术后鞘内注射生理盐水;CCI组坐骨神经结扎后鞘内注射生理盐水;2-PMPA组坐骨神经结扎后鞘内注射2-PMPA 100 μg.所有组每次给药剂量均为10μl,每日1次,连续7d.分别于术前及术后7d时,以热缩足潜伏期(TWL)和机械缩足阈值(MWT)测定大鼠痛阈,然后处死大鼠,采用免疫荧光和Western blot法测定脊髓水平TRPV1的表达.结果:三组大鼠术后7dTWL和MWr值分别为(17.8±1.1)、(5.5±1.0)、(12.0±1.4)s和(13.1±1.2)、(4.3±0.9)、(10.5±1.0)g.与sham组比较,CCI组术后7d时TWL和MWT值均降低,脊髓TRPV1表达水平显著升高,差异有统计学意义(P＜0.05);与CCI组比较,2-PMPA组术后7d时TWL和MWT值均升高,脊髓TRPV1表达水平显著降低,差异有统计学意义(P＜0.05).结论:鞘内注射NAAG肽酶抑制剂可以有效地治疗神经病理性疼痛,其作用机制可能与抑制脊髓水平TRPV1的表达有关.

Glial cell line-derived neurotrophic factor (GDNF) is a potent neurotrophic factor for midbrain dopamine (DA) neurons, while the DA neurons in the ventral tegmental area (VTA) is a crucial part of the neural circuits associated with drug addiction. Recently, more and more evidence suggests that GDNF plays an important role in negatively regulating the neuroadaptations induced by chronic exposure to drugs, which was thought to be the neurobiological basis of drug addiction, but the underlying mechanism is still unknown. More recently, the neural cell adhesion molecule (NCAM), which plays an important role in the process of neural plasticity, has been identified as an alternative signaling receptor for GDNF. The purpose of this study was to investigate whether NCAM was involved in the effects of GDNF on the neuroadaptations induced by chronic morphine exposure. Immunostaining results showed that NCAM was widely expressed in the VTA of rats, including all the DA neurons. The results also showed that the phosphorylation of NCAM-associated FAK, but not the total NCAM, was upregulated by GDNF, and this upregulation was inhibited by pre-treatment with the NCAM function-blocking antibody. Moreover, pre-treatment with the antibody could antagonize the effect of GDNF on inhibiting the neuroadaptations induced by chronic morphine exposure, including the decreases of the number and length of neurites and the size of cell bodies of VTA dopamine neurons, as well as the increase of tyrosine hydroxylase in the VTA dopamine neurons. These results suggest that NCAM signaling is involved in the negative regulatory effects of GDNF on chronic morphine-induced neuroadaptations.

胶质细胞系源性神经营养因子(glial cell line-derived neurotrophic factor,GDNF)是转化生长因子β超家族的一员,具有多种重要的生物学功能.GDNF对中脑多巴胺(dopamine,DA)能神经元具有高特异的营养作用,而中脑腹侧被盖区(ventral tegmental area,VTA)的DA能神经元是药物成瘾相关神经环路的重要组成部分.越来越多的研究表明,GDNF通过作用于VTA的DA能神经元,在药物成瘾中发挥重要的调节作用,有望成为防治药物成瘾的一个新靶向.本文围绕GDNF对药物奖赏、复吸及成瘾相关生化适应性改变的调控及其机制作一简要综述.

Glial-cell-line-derived neurotrophic factor (GDNF) has been shown to protect dopaminergic (DA) neurons against 6-hydroxydopamine (6-OHDA) toxicity. The mechanism underlying the antiapoptosis role of GDNF still needs further studies. We previously observed that nuclear factor-kappaB (NF-kappa B) signaling pathway, i.e. p65/p52, mediated the antiapoptosis role of GDNF in MN9D cells. Here, the DA cell line MN9D was used to explore the mechanisms underlying NF-kappa B p65/p52-mediated protection role of GDNF in DA neurons. The results showed that GDNF pretreatment blocked the apoptotic effects induced by 6-OHDA, with the upregulation of the antiapoptotic protein, Bcl-2 and Bcl-w, as well as the downregulation of the proapoptotic proteins, Bax and Bad. Furthermore, when sip100 plasmids were transfected into MN9D cells to inhibit the expression of p100, which was the precursor of p52, the effects of GDNF on upregulating Bcl-2 and Bcl-w were attenuated. These results indicated that GDNF could protect MN9D cells from apoptosis induced by 6-OHDA via upregulating Bcl-2 and Bcl-w expressions and downregulating Box and Bad expressions. Moreover, NF-kappa B p65/p52 signaling mediated the effects of GDNF on Bcl-2 and Bcl-w expressions.

Glial cell line-derived neurotrophic factor (GDNF) is a potent protective factor for dopaminergic (DA) neurons, but the signaling mechanisms underlying the effect of GDNF on these neurons remain obscure. Here, both our in vivo and in vitro studies demonstrate that the majority of DA neurons express the NF-κB-inducing kinase (NIK), which is the essential kinase for mediating activation of the new alternative NF-κB signaling pathway. Additionally, we also show that GDNF induced the time/dose-dependent phosphorylation of IκB kinase α (IKKα) and p100, facilitated the processing of p100 to p52 and accelerated the translocation of NF-κB dimmers into the nuclei of DA neurons. We furtherly found that the dimmer which translocate into the nucleus was RelA/p52 not RelB/p52. Meanwhile, the attenuation of 6-OHDA-induced DA neuronal apoptosis due to GDNF was reversed subsequent to the inhibition of p100 expression by RNAi while the neuroprotective effect of GDNF on injured DA neurons was strengthened by the overexpression of p100. Our data, therefore, indicate that a new alternative NF-κB signaling pathway, which was not the classic pathway but different from the non-canonical pathway, exists in DA neurons and mediates the neuroprotective effect of GDNF on these neurons.

Objective To compare the effects of procaine under different pH conditions on the potential amplitude and propagation velocity of the compound action of toad sciatic nerve and to determine the 50% effective pH of procaine hydrochloride when the toad sciatic nerves were blocked.Methods 30 isolated toad sciatic nerve cords were divided into 6 groups and treated with procaine hydrochloride with pH of 3,4,5,6,7 and 8,respectively.The amplitude and propagation velocity of the compound action potential were recorded before and after procaine treatment.26 left sciatic nerves of toad were prepared and treated with procaine under pH conditions of 5,4,3.2,2.56,2.05 by sequential therapy to determine the 50% effective pH of procaine hydrochloride with the flexion reflex as a positive index.Results The amplitutd and the propagation velocity of the compound action potential of toad sciatic nerve changed significantly under procaine of pH 6.The confidence interval (95% ) of 50% effective pH procaine was 2.28-2.77.Conclusion The nerve block effects of procaine vary with different pH conditions.

Objective To investigate the effect of different doses of sodium oxybate on the convulsions and mortality rate of mice with ropivacaine poisoning.Methods 40 mice were randomized into 4 groups(n=10 each) and received intraperitoneal injections of sodium oxybate of three different doses or the same volume of normal saline,respectively.5 minutes later,all the mice received an intraperitoneal injection of ropivacaine in a toxic dose and the convulsion latency,duration,seizure incidence and mortality of the 40 mice were observed and recorded.Results Compared with the normal saline group,the sodium oxybate groups had a lower convulsion rate,longer latency of the convulsion,shorter duration and reduced mortality.Conclusion Sodium oxybate could decrease ropivacaine toxicity with a dose-dependent response.

Glial cell line-derived neurotrophic factor (GDNF) has an essential role in the survival and maturation of the dopaminergic (DA) neurons in the substantia nigra (SN) of mammalian embryonic brain. In addition to Ret, cell adhesion molecules (CAMs) were also proposed to function as transmembrane signaling receptors of GDNF. The present study was to investigate whether these transmembrane receptors of GDNF were correlated with the tyrosine hydroxylase (TH) expression of SN DA neurons during early developmental stage. RT-PCR and Western blot were performed to detect TH expression in SN of perinatal rats at mRNA and protein level respectively; meanwhile, Western blot was performed to detect the expressions of the transmembrane proteins including Ret, neural cell adhesion molecule-140 (NCAM-140), integrin β1 and N-cadherin. The results showed that TH mRNA expression was positively correlated with both Ret and N-cadherin protein, while there was no correlation with NCAM-140 and integrin β1; TH protein expression was correlated with all of these transmembrane molecules. These data suggested that the expression of either TH mRNA or TH protein was subject to the mediation of different transmembrane receptor combinations of GDNF.

In order to define the expression of integrin β1 in mesencephalic substantia nigra of preinatal and postnatal rats and to explore the possible roles of integrin β1 in the developmental course of substantia nigra cells,the RT-PCR,Western blot analysis and immunohistochemistry staining were performed to determine the integrin β1 expression in mesencephalic substantia nigra of healthy Prenatal and postnatal SD rats,aged 16,18 and 20 embryonic days(E16,E18 and E20)and 1,3,7,14 and 21 postnatal days(P1,P3,P7,P14 and P21).The results of RT-PCR and Western blot analysis showed that the mRNA and protein of integrin β1 were obviously expressed in rat substantia nigra at all of the time points of detection in a similar manner.Integrin β1 was highly expressed in substantia nigra from E16 to P7 period;then the level decreased significantly on P14,and such lowered expression was maintained during the rest of the development,showing no differences between P14 and P21.Immunohistochemistry staining showed that lots of integrin β1 positive cells were presented in the substantia nigra at all of the time points.The cell bodies increased in size gradually from E16 to P14,and there was no significant difference between P21 and P14.On the other hand,the number of integrin β1 positive cells per area(cell density)was rather steady,revealed no variation from E16 to P7,but decreased obviously at P14,and this lowered density was maintained during the rest of the development,with no differences between P14 and P21.The above results indicate that integrin β1 in mesencephalic substantia nigra of rats was highly expressed during the developmental period from E16 to P7 and markedly decreased from P14 to P21.These changes coincide with the timetable of the natural apoptosis of dopaminergic neurons,suggesting that the expression of integrin β1 was associated with the apoptosis of dopaminergic neurons in rat substantia nigra during development.

Glial cell line‐derived neurotrophic factor (GDNF) is a potent neurotrophic factor for the substantia nigra (SN) dopamine (DA) neurons. The transmembrane signaling of GDNF is mediated by a unique receptor system, including the ligand binding receptor GDNF family receptor α (GFRα) and the transmembrane signaling receptor Ret or neural cell adhesion molecule‐140 (NCAM‐140). Here, we found that another transmembrane cell adhesion molecule, integrin, a heterodimer consisting of α and β subunits, also mediates the transmembrane signaling of GDNF. The results showed that the level of phosphorylated Src homology 2 domain containing (Shc), which was associated with the cytoplasmic domain of integrin β1, increased after GDNF administration. Coimmunoprecipitation analysis demonstrated that integrin β1 could form a complex with GFRαl. The simulation of molecular modeling showed that four H‐bonds were formed between integrin β1 and GFRα. These data indicate that integrin β1 is involved in the transmembrane signaling of GDNF and suggest that integrin β1 may be an alternative signaling receptor for GDNF. J. Comp. Neurol. 509:203–210, 2008. © 2008 Wiley‐Liss, Inc.

Glial cell line-derived neurotrophic factor (GDNF) exerts its biological effects via a multi-component receptor system including the ligand binding receptor – GDNF family receptor-alpha1 (GFRα1) and the signaling receptor – RET tyrosine kinase. Recently, the neural cell adhesion molecule (NCAM) has been identified as an alternative signaling receptor for GDNF. The purpose of this study was to investigate whether NCAM could mediate the protective effect of GDNF on injured dopamine (DA) neurons and to determine which cytoplasmic signal molecule associated with NCAM was activated while GDNF performing this effect. The results showed that the phosphorylation of NCAM-associated Fyn was upregulated with GDNF treatment, and this upregulation was inhibited by pre-treatment with the NCAM function-blocking antibody. Moreover, pre-treatment with the antibody could abolish the effect of GDNF on promoting the neurite outgrowth of these DA neurons, except for the effect of GDNF on promoting the expression of tyrosine hydroxylase (TH) in these DA neurons. These results suggest that NCAM is involved in the promotive effect of GDNF on the neurite outgrowth in lesioned DA neurons, but not involved in the promotive effect of GDNF on TH expression in these neurons.

BACKGROUND: Cellular adhesion molecule mediates the effects of glial cell line-derived neurotrophic factor in dopaminergic neurons during nervous system development. It is assumed that cellular adhesion molecule plays an important role in dopaminergic neuron development.OBJECTIVE: To investigate N-cadherin expression in the midbrain substantia nigra during rat development.DESIGN, TIME AND SETTING: The developmental biology, controlled study was performed at the Laboratory of Research Center of Neurobiology, Xuzhou Medical College, China from April to October 2007.MATERIALS: Sprague Dawley rats (embryonic days 16, 18, and 20, as well as postnatal days 1, 3, 7, 14 and 21) were selected for this study. N-cadherin antibody was purchased from Santa Cruz, USA. METHODS: N-cadherin expression in the midbrain substantia nigra of perinatal rats was detected using reverse transcription polymerase chain reaction, Western blot, and immunohistochemistry methods. N-cadherin-positive cells were counted.MAIN OUTCOME MEASURES: N-cadherin mRNA. protein, and positive cells in the rat midbrain substantia nigra were quantified.RESULTS: The results of reverse transcription polymerase chain reaction and Western blot demonstrated that altered N-cadherin mRNA levels were similar to protein levels in the midbrain substantia nigra. N-cadherin mRNA and protein expression was low in the midbrain substantia nigra of embryonic day 16 but gradually increased, and reached a peak at postnatal day 1. N-cadherin mRNA and protein levels were still high at postnatal days 3 and 7, but Significantly decreased at postnatal day 14. There was no significant difference in N-cadherin mRNA and protein expression between postnatal days 14 and 21 (P > 0.05). The immunohistochemistry results demonstrated that there was no significant difference in the quantity of N-cadherin-positive cells per area in rats from embryonic day 16 to postnatal day 7 (P > 0.05). The quantity of N-cadherin-positive cells per area was significantly decreased in rats at postnatal day 14. There was no significant difference in the number of N-cadherin-positive cells per area between postnatal days 14 and 21 (P > 0.05).CONCLUSION: N-cadherin expression was reduced during embryonic stages, but reached a peak at postnatal days 1-7, and then gradually decreased in the rat midbrain substantia nigra.

Calbindin-D28K is a calcium-binding protein in neuronal cytoplasm, which has the capability to protect neurons from degeneration. It was reported that glial cell line-derived neurotrophic factor (GDNF) increased calbindin-D28K expression in dopaminergic neurons in vitro. It was observed in our research that GDNF also enhanced the expression of calbindin-D28K in adult rat substantia nigra neurons in vivo. To investigate the intracellular signaling pathways underlying the calbindin-D28K expression induced by GDNF, immunoblot and immunoprecipitation analyses were performed in our present study. Our results showed that injection of GDNF alone into substantia nigra of an adult rat brain increased the calbindin-D28K expression; meanwhile, the phosphorylation level of protein kinase B (Akt) and extracellular signal-regulated kinase 1/2 (ERK1/2) increased. However, the calbindin-D28K expression induced by GDNF was specifically blocked by the inhibitor of phosphatidylinositol 3-kinase (PI3K), but the inhibitor of ERK1/2 did not block the calbindin-D28K expression. Furthermore, GDNF administration also caused the nuclear factor kappaB (NF-kappaB/p65), to translocate from cytoplasm into the nucleus, and the inhibitor of PI3K effectively blocked the translocation. Immunoprecipitation assay results further demonstrated that it was the p65/p52 complex of NF-kappaB, rather than the p65/p50 complex that translocated into the neuronal nucleus. The calbindin-D28K expression induced by GDNF was also inhibited when the NF-kappaB signaling pathway was blocked by Helenalin. These results described a novel mechanism by which the activation of PI3K/Akt-->NF-kappaB (p65/p52) signaling pathway could play a role in the calbindin-D28K expression induced by GDNF.

Glial cell line-derived neurotrophic factor (GDNF) can exert neuroprotective effects on the substantia nigra pars compacta (SNc) dopaminergic (DA) neurons that are undergoing degeneration in Parkinson's disease (PD). In an attempt to investigate the molecular signaling mechanisms underlying GDNF protection the DA neurons from degeneration, we established early PD rat models in which the DA neurons in SNc were degenerating. Whether the cytoplasmic NF-kappaB signaling pathway was involved in the protection of GDNF on the degenerating DA neurons was examined in the present study. The results showed that the nuclear NF-kappaB p65 levels in the DA neurons increased when GDNF was injected into SNc of early PD rat models. Immunoprecipitation assays showed that the nuclear NF-kappaB p65/p52 complex levels increased after GDNF administration, while the p65/p50 complex levels decreased. These results indicated that GDNF could activate the NF-kappaB signaling pathway in the degenerating DA neurons. And it was the noncanonical NF-kappaB signaling pathway, which contained the NF-kappaB p65/p52 complex that was involved in the effects of GDNF on DA neurons.