3种麻醉剂对蟾蜍离体坐骨神经电生理特性影响的比较研究

使用BL-420生物机能实验系统,采用细胞外记录神经干动作电位的方法,观察了氨基甲酸乙酯、水合氯醛和戊巴比妥钠3种麻醉剂对蟾蜍离体坐骨神经电生理特性的影响.结果:3种麻醉剂均可使坐骨神经的兴奋性降低、动作电位时程延长;另外,氨基甲酸乙酯和水合氯醛对神经的传导速度和动作电位幅度抑制作用较强,戊巴比妥钠对神经传导速度抑制作用较弱,但中浓度的戊巴比妥钠有增加动作电位幅度的作用.     

Tropic1808基因重组蛋白对损伤坐骨神经脊髓细胞凋亡的影响

探讨Tropic1808基因重组蛋白对损伤坐骨神经的新生大鼠脊髓细胞凋亡影响,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Tropic1808基因重组蛋白,阳性用神经生长因子、阴性用生理盐水作为对照;术后3、6、12h经TUNEL法染色,在光镜、电镜和图像分析系统下,了解L4－L5段脊髓细胞凋亡情况。得到生理盐水组的脊髓出现大量绸亡细胞;Tropic1808基因重组蛋白组凋亡细胞数量较生理盐水组显减少;Tropic1808基因重组蛋白组与神经生长因子组之间凋亡细胞数量的差别无显性意义。说明Tropic1808基因重组蛋白有保护受损神经组织,减少细胞凋亡的作用。     

野木瓜注射液对大鼠外周痛觉信息传导的影响

对完整Wistar大鼠模型,应用微电极细胞外记录技术,观察了在坐骨神经处分别加入10%,25%,50%,75%和95%的野木瓜注射液前后,电刺激大鼠坐骨神经诱发的脊髓背角广动力范围神经元放电活动的变化.结果表明:野木瓜注射液在坐骨神经处加药时能降低大鼠脊髓背角广动力范围神经元的诱发放电频率和幅度(P0.05),并具有浓度依赖性,这与野木瓜注射液对离体背根神经节细胞产生的效应是一致的.野木瓜注射液可以在外周水平上阻滞痛觉信息的传导,这可能是其产生镇痛作用的原因之一.     

亚砷酸钠对大鼠离体坐骨神经干复合动作电位的影响

应用电生理方法观察了不同浓度的亚砷酸钠对大鼠离体坐骨神经干复合动作电位的幅度、阈强度、传导速度及持续时间的影响。结果表明:亚砷酸钠溶液浸泡大鼠坐骨神经干30分钟,当浓度高于3×10-4mol/L时,复合动作电位的幅值较对照组明显降低(P<0.01)。复合动作电位的阈强度随亚砷酸钠浓度的升高而增加,差异有显著性(P<0.01)。复合动作电位的传导速度随亚砷酸钠浓度的升高而变慢,但只有亚砷酸钠浓度高于10-3mol/L时,复合动作电位传导速度与对照组相比差异才有显著性(P<0.01)。复合动作电位的持续时间随亚砷酸钠浓度增加而延长,但与对照组相比无差异(P>0.05)。这说明亚砷酸钠可影响大鼠坐骨神经干复合动作电位。     

bFGF促进大鼠坐骨神经损伤修复的电生理学

用大鼠坐骨神经钳夹损伤模型和电生理学方法研究碱性成纤维细胞生长因子（ｂＦＧＦ）对周围神经损伤修复过程中的功能影响。分别对治疗组和对照组进行２、３、４和５周的观察，结果显示：治疗组受损神经的动作电位幅值及传导速度的恢复率较对照组明显加快，差异有显著性意义。表明ｂＦＧＦ能促进损伤的外周神经再生及功能恢复。     

鸽上纹状体神经元对桡神经和坐骨神经传入冲动的反应

在61只家鸽上纹状体中,用玻璃微电极共记录到138个对电刺激桡神经和坐骨神经发生反应的单位.根据诱发反应放电型式,可分为三类:①单个或短串放电反应.②长串放电反应.③抑制性反应.其中①类细胞有116个.上纹状体神经元对躯体神经刺激反应的潜伏期差异较大,多数桡神经传入的诱发反应具有长潜伏期特征.结合解剖学资料对潜伏期差异的原因进行了讨论.认为,短潜伏期反应可能是由DIVA-Wulst通路直接传入引起,长潜伏期反应可能是经DLP-NI/NC-Wulst通路间接传入引起.     

Testosterone derivatives are neuroprotective agents in experimental diabetic neuropathy

In this study we have assessed the effect of testosterone (T), dihydrotestosterone (DHT) and 5αandrostan-3α, 17β-diol (3α-diol) therapies on diabetic neuropathy. Diabetes was induced in adult male rats by the injection of streptozotocin and resulted in decreased T and increased 3α-diol levels in plasma and in decreased levels of pregnenolone and DHT in the sciatic nerve. Moreover, a reduced expression of the enzyme converting Tinto DHT (i.e., the 5α-reductase) also occurs at the level of sciatic nerve, suggesting that the decrease of DHT levels could be due to an impairment of this enzyme. Chronic treatment for 1 month with DHT or 3α-diol increased tail nerve conduction velocity and partially counteracted the increase of thermal threshold induced by diabetes. Treatment with DHT increased tibial Na⁺,K⁺-ATPase activity and the expression of myelin protein P0 in the sciatic nerve.DHT, 3α-diol and T reversed the reduction of intra-epidermal nerve fiber density induced by diabetes. These observations indicate that T metabolites can reverse behavioral, neurophysiological, morphological and biochemical alterations induced by peripheral diabetic neuropathy. I. Roglio, R. Bianchi: These authors contributed equally to this study. Received 4 January 2007; received after revision 13 February 2007; accepted 27 March 2007     

Nerve regeneration factor promotes nerve regeneration in rat

Nerve regeneration factor (NRF) extracted from an oral liquid of traditional Chinese medicine, as a nerve growth decoction has been reported by previous studies to exert effects of promoting nerve growth and preventing neuron apoptosis. For new insights into the function of NRF on primary cultured neurons, we investigated the neurite outgrowth in cultured rat dorsal root ganglion (DRG) explant treated with NRF by immunofluorescence and the gene and protein expressions of neurofilament-H(NF-H) and growth associated protein 43 (GAP43) in the cultured rat DRG neurons by real-time quantitative RT-PCR and Western blotting, respectively. In addition, we used a rat model of sciatic nerve crush to evaluate the effect of NRF on regeneration of injured sciatic nerve by a combination of walk track analysis, electrophysiological and histological assessments. The in vitro experiments indicated that NRF promoted the neurite growth of DRGs and the expression of NF-H and GAP43 at mRNA and protein levels in DRG neurons, and in vivo experiments showed that NRF improved peripheral nerve regeneration and functional recovery.     

纳米氧化锌对蛙坐骨神经动作电位的影响

目的:观察纳米氧化锌对蛙坐骨神经干经过不同的时间处理,所产生的动作电位变化的情况。方法:配制纳米氧化锌溶胶,设置不同的处理时间(10min、20m、30min、50min和130min),采用Medlab生物信号采集系统来记录蛙坐骨神经的动作电位情况。结果:经过不同时间的纳米氧化锌处理,均能显著促进蛙神经干动作电位幅度的增加;合适的处理时间(20min-50min)能显著增加动作电位的传导速度;但对神经干不应期和动作电位时程的影响不显著,说明纳米氧化锌影响了周围神经细胞膜上离子或通道的活动状态。