家兔人工通气和窒息时刺激舌咽神经对膈神经放电和血压的影响

切断大鼠舌咽神经(包括窦神经)可导致通气反应减弱。刺激舌咽神经可引起膈神经放电抑制,呼气相刺激则诱发成束放电。吸气相刺激舌咽神经咽支引起膈神经放电加强,呼气相出现兴奋反应。但是,舌咽神经舌支能否影响呼吸和血压,咽支对血压有无影响尚不清     

结蛋白在正常和心脏基因突变型墨西哥美西螈胚胎心脏中的分布

结蛋白是中间丝的一种,在心肌细胞发育中参与肌原纤维的组成和定位。墨西哥美西螈(Am-blystoma mexicanum)有一种自然产生的隐性心脏突变基因,称为基因C,其表现为心脏发育中肌原纤维的定位障碍,心肌细胞不能收缩,心脏不搏动,最终均在胚胎后期死亡。电镜检查已证实,正常美西螈胚胎心脏具有定位好的肌原纤维,而心脏基因突变型胚胎心脏心肌细胞中没有明显的肌节,仅有少量排列不规则、漫散分布的肌原纤维(Lemansk, 1973a;1973b)。对研究胚胎心脏心肌细胞的发生而言,美西螈心脏基因突变型胚胎心脏是一种理想的实验动物模型。本研究中,作者用共聚焦激光扫描显微镜结合免疫组织化学观察,比较结蛋白在正常和心脏基因突变型胚胎心脏中的分布,以进一步探讨结蛋白与心肌细胞发生的关系。     

版纳鱼螈胚胎和幼体鳃的退化观察

为了解版纳鱼螈(Ichthyophis bannanicus)胚胎和幼体鳃的退化特征,同窝卵中8枚在胚胎成熟阶段早期被随机取出剖产,随后余下的9枚卵在胚胎成熟阶段晚期时孵出或剖产,观察幼体或胚胎鳃的变化。成熟阶段早期的胚胎,初时其鳃色鲜红,鳃枝充盈,鳃丝与鳃轴近乎垂直;随后鳃色发白,鳃枝疲软,鳃丝卷曲,鳃丝与鳃轴夹角变小。成熟阶段晚期的胚胎和刚孵出的幼体,初时其鳃色纯白,鳃枝疲软,鳃丝卷曲,鳃丝与鳃轴夹角较小;随后鳃逐渐脱落。观察发现,版纳鱼螈胚胎或幼体鳃的退化模式不是重吸收,也不是重吸收加脱落,而仅为脱落。鳃退化过程经历外鳃供血减少-供血停止-鳃枝组织死亡和脱落3个阶段,每个阶段都有明显的外部形态特征。胚胎进入成熟阶段后,越早孵化,鳃枝留存越多,反之,鳃枝留存越少。发白后的鳃枝随机性脱落。     

威宁趾沟蛙早期胚胎发育的观察

用从野外采集受精卵室内观察的方法研究了威宁趾沟蛙的早期胚胎（8～25期）发育过程。结果表明：受精卵在水温为15±1℃的条件下从囊胚早期到鳃盖褶完成期需要519．23±1．57h,早期胚胎发育的特点是：大多数胚胎的孵化是在肌肉效应期;鳃盖褶完成中、后期胚体能到水面上活动;胚体纵轴伸长出现在神经褶后期;出水孔始于鳃盖褶完成期的胚体左侧靠前处;左侧鳃盖褶先发育完成。     

瘰螈属一新种——龙里瘰螈（有尾目：蝾螈科）

在贵州省龙里县水场乡采集到一批瘰螈标本,与瘰螈属已知物种比较后,确定其为一新种,即龙里瘰螈(Paramesotriton longliensis Li,Tian,Gu et Xiong sp.nov)。新种与尾斑瘰螈(Paramesotriton caudopunctatus)相似,但新种由于上鳃骨后端上翘,成体头部后端两侧鳃迹部位各有1个明显突起;体背嵴棱强烈隆起;指、趾两侧无缘膜,指、趾末端有黑色角质鞘;肛后尾的腹鳍褶橘红色,约在1/2处此颜色消失;雄螈尾后段浅紫红色无斑纹。统计并记述了新种的外形、头骨特征、染色体组型、生物学资料。     

PTEN基因对早期胚胎神经嵴细胞迁移的作用研究

目的 初步探讨PTEN基因在早期神经嵴细胞迁移中的作用.方法 首先胚胎整体的原位杂交和免疫荧光方法检测鸡胚胎内源性的PTEN基因及蛋白水平的表达情况;其次,利用鸡胚胎体内半侧神经管转染的方法,使神经管一侧PTEN基因过表达,对侧神经管为正常对照侧;最后,通过Pax7的整体胚胎免疫荧光表达观察PTEN基因对其标记的部分神经嵴细胞迁移的影响.结果 内源性PTEN基因在mRNA和蛋白水平表达显示,其在早期胚胎HH4期的神经板即开始明显的表达;通过半侧过表达PTEN基因后观察到过表达PTEN基因侧的头部神经嵴细胞迁移与对照侧相比明显受到抑制,但对躯干部的影响并不明显.结论 PTEN基因可能抑制早期胚胎头部神经嵴细胞的迁移.     

中国肥螈属(两栖纲:蝾螈科)一新种——弓斑肥螈Pachytriton archospotus sp. nov.

本文记述两栖纲蝾螈目蝾螈科一新种,新种具肥螈属(Pachytriton)系列特征,与肥螈属已知2种比较有明显区别.如1)本新种与黑斑肥螈(Pachytriton brevipes)相似,体表具黑色小圆斑,但新种具额鳞弓、上鳃骨直而与后者不同;无斑肥螈(Pachytriti on labiatus)(地模标本)虽具额鳞弓,但上鳃骨明显弯曲,体表无黑色小圆斑;2) 新种吻短,吻长小于眼间距,黑斑肥螈吻长大于眼间距,无斑肥螈吻长大于或等于眼间距, 它们的头型明显不同,虽然三者头长均大于头宽,但头长、吻长、眼间距差异显著;3)繁 殖期新种雄体肛区不明显肿胀,肛裂周边中、后部生殖乳突长,而且多,十分醒目;黑斑肥 螈和无斑肥螈繁殖期肛区明显肿胀膨大,生殖乳突较短、且稀.经统计分析三种肥螈的头体长、头长、头宽、吻长和眼间距存在显著差异     

文县疣螈在重庆境内分布的补充调查

2005～2008年在重庆云阳县和奉节县对文县疣螈 Tylototriton wenxianensis 进行了10处实地考察,其中9处看见或采集到标本,1处为寻访调查;在1处观察到其求偶行为.结合文献和标本查阅结果,更具体地了解到重庆市文县疣螈的分布情况和各地种群生存现状的信息,从而为该物种的地区性保护提供相关策略.     

背瘤丽蚌胚胎发育的初步研究

用显微技术研究了背瘤丽蚌(Lamprotula leai)胚胎发育和钩介幼虫结构。结果表明,背瘤丽蚌卵为均黄卵,受精卵分布在雌蚌内、外鳃腔中进行胚胎发育;胚胎发育同步;胚胎发育过程包括受精卵、卵裂期、囊胚期、原肠期、膜内钩介幼虫期和钩介幼虫期;卵裂为螺旋不等完全卵裂;未受精的成熟卵在鳃腔内退化;胚胎发育期与胚胎、外鳃和内鳃颜色相关;怀卵母蚌胚胎在外界环境变化时容易全部流产。分析认为背瘤丽蚌胚胎发育期的繁殖特征可指导人工苗种生产。     

镇海棘螈早期个体发育研究

根据野外观察和室内实验 ,对镇海棘螈的早期个体发育过程进行了研究。结果显示 ,镇海棘螈早期发育过程与琉球棘螈的个体发育过程非常相似 ,它们的平衡枝均不发达且在前肢芽晚期迅速消失。温度和湿度对胚胎发育具有显著影响。室温下 ,从受精卵到孵化需 2 9d左右。孵化幼体体长呈配合对数曲线增长 ,其体全长 (S)与日龄 (T)的关系可表示为S =1 2 974 9+6 2 398lnT(Sig.F <0 0 1 )。水生生活阶段为 58～ 88d。室内幼体的水生发育时间和变态个体大小与野外的情况有较大的差异 ,可能与营养条件和自然条件下的持续干旱有关。变态前的外鳃萎缩期是镇海棘螈早期个体发育过程中的死亡高峰期。     

索曼和吗啡对猫膈神经和肋间外神经放电的影响

在乌拉坦氯醛糖混合麻醉猫上,平静呼吸时膈神经和肋间外神经α纤维单纤维放电时程、冲动数、冲动频率及休止期经统计处理无明显差别。切断双侧迷走神经后呼吸深慢,两种神经的冲动频率升高、放电时程延长及冲动数增多。窒息时两种神经电活动先增强,然后同时停止活动。索曼0.2—3μg 椎动脉或10—20μg/kg 静脉注射后,主要抑制膈神经放电的占85%和87%,无主要抑制肋间外神经的反应。椎动脉注射吗啡0.5—5mg,主要抑制肋间外神经放电的反应则占58%,无抑制膈神经放电的反应。从膈神经元所在的颈髓局部浸润索曼不能停止膈神经节律吸气放电。以上结果表明,主要支配膈神经的延髓呼吸神经元背侧组(DRG)和主要支配肋间外神经的腹侧组(VRG)在平静呼吸时活动无明显差异。而索曼和吗啡可使这两个细胞核团表现不同的反应。     

刺激家兔肾内感受器和肾传入神经的血流动力学效应

在39只麻醉家兔观察刺激肾脏机械和化学感受器以及电刺激肾传入神经的血流动力学效应。增加输尿管压8—22mmHg 及经输尿管向肾盂内逆向灌注 NaCl(1.0 mol/L)及 KCl(0.15mol/L)溶液时,引起平均动脉压(MAP)和心率(HR)下降;切断双侧缓冲神经后,MAP 降低更为显著。电刺激肾传入神经时,HR 减慢,MAP、肠系膜动脉和后肢动脉灌流压降低,左心室收缩压及其微分值下降,心输出量(CO)和总外周阻力(TPR)减小;切断双侧窦神经和减压神经后,除 HK、CO 和 TPR 外,其余各血流动力学指标的减弱更为显著。由此提示,动脉压力感受器反射对肾传入神经激活的心血管效应有缓冲作用。     

Age-related changes of elements with their relationships in human cranial and spinal nerves

To elucidate compositional changes of peripheral nerves with aging, the authors investigated age-related changes of elements and their relationships in the optic, trigeminal, vagus, median, radial, ulnar, femoral, sciatic, tibial, and common peroneal nerves by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 10 men and 12 women, ranging in age from 65 to 91 yr. It was found that although accumulations of Ca and P occurred only in the trigeminal nerve at old age, it hardly occurred in the optic, vagus, median, radial, ulnar, femoral, sciatic, tibial, and common peroneal nerves at old age. The average contents of Ca and P were three and two times higher in the trigeminal nerve than in the other nine kinds of nerve, respectively. Likewise, the average content of Mg was a little higher in the trigeminal nerve compared with the other nerves. With regard to the relationships among elements, significant direct correlations were found among the contents of Ca, P, S, and Mg in most, but not all, 10 kinds of nerve. In the trigeminal nerve, a significant inverse correlation was found between the contents of S and the other elements, such as Ca, P, and Mg. Regarding the relationships between the contents of S and other elements, the nerves, except for the trigeminal nerve, differed from those found in the arteries previously reported.     

Reverse Phase High-Performance Liquid Chromatography of Cerebrosides, Sulfatides and Ceramides: Microanalysis of Homolog Composition Without Hydrolysis and Application to Cerebroside Analysis in Peripheral Nerves of Adrenoleukodystrophy Patients

Abstract: Reverse phase high-performance liquid chromatographic analyses of nonhydroxy-and hydroxycerebrosides and sulfatides, as well as ceramides, have been developed. Cerebrosides, ceramides and sulfatides were perbenzoylated then desulfated before chromatographic analysis. These sphingolipid derivatives can be separated according to their fatty-acid composition by using an ODS 5-μ, column (reverse phase column containing octadecylsiloxane derivative of silica, of 5-μm particle size) and solvent systems consisting of various proportions of acetonitrile and methanol. The retention time of an individual homolog appears to be unaffected by the 4-trans double bond of the sphingosine moiety. These methods allow us to determine fatty-acid compositions of ceramides, cerebrosides and sulfatides without hydrolysis. Homolog composition of cerebrosides in peripheral nerve from adrenoleukodystrophy patients was investigated by using reverse phase high-performance liquid chromatography and was found not to be significantly different from control nerves.     

Age-related variations of elements as compared among optic, radial, and sciatic nerves

To elucidate changes of peripheral nerves with aging, the authors studied age-related changes of element contents in the optic, radial, and sciatic nerves by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of seven men and seven women, ranging in age from 61 to 97 yr. The contents of phosphorus and sulfur remained constant through ages 61 to 97 yr in three nerves, the optic, radial, and sciatic nerves. It was found that there were age-related differences in calcium content among the optic, radial, and sciatic nerves: The calcium content of the optic nerve increased progressively with aging; in the radial nerve, it was hardly changed with aging; in contrast, the calcium content of the sciatic nerve decreased gradually with aging. In addition, it was found that in the radial nerve there were moderate correlations between age and zinc or sodium content, whereas significant correlations between age and the content of silicon or iron were found in the sciatic nerve. Furthermore, there was a correlation between the silicon and iron contents in the sciatic nerves.     

Fabrication and properties of a porous chitin/chitosan conduit for nerve regeneration

A porous, biodegradable, natural chitin/chitosan nerve conduit was constructed. Scanning electron microscopy confirmed that it was homogeneous and highly porous. FT-IR spectra showed that there were no residues arising from the preparation process in the conduit. Addition of chitin to the chitosan solution increased the mechanical strength and maximum tensile strength from 7.2 to 9.6 MPa. Preliminary animal tests indicated that porous chitin/chitosan conduits did not swell in vivo and were compatible with surrounding tissue.     

Fibrin matrices with affinity‐based delivery systems and neurotrophic factors promote functional nerve regeneration

Glial‐derived neurotrophic factor (GDNF) and nerve growth factor (NGF) have both been shown to enhance peripheral nerve regeneration following injury and target different neuronal populations. The delivery of either growth factor at the site of injury may, therefore, result in quantitative differences in motor nerve regeneration and functional recovery. In this study we evaluated the effect of affinity‐based delivery of GDNF or NGF from fibrin‐filled nerve guidance conduits (NGCs) on motor nerve regeneration and functional recovery in a 13 mm rat sciatic nerve defect. Seven experimental groups were evaluated consisting of GDNF or NGF and the affinity‐based delivery system (DS) within NGCs, control groups excluding the DS and/or growth factor, and nerve isografts. Groups with growth factor in the conduit demonstrated equivalent or superior performance in behavioral tests and relative muscle mass measurements compared to isografts at 12 weeks. Additionally, groups with GDNF demonstrated greater specific twitch and tetanic force production in extensor digitorum longus (EDL) muscle than the isograft control, while groups with NGF produced demonstrated similar force production compared to the isograft control. Assessment of motor axon regeneration by retrograde labeling further revealed that the number of ventral horn neurons regenerating across NGCs containing GDNF and NGF DS was similar to the isograft group and these counts were greater than the groups without growth factor. Overall, the GDNF DS group demonstrated superior functional recovery and equivalent motor nerve regeneration compared to the isograft control, suggesting it has potential as a treatment for motor nerve injury. Biotechnol. Bioeng. 2010;106: 970–979. © 2010 Wiley Periodicals, Inc.     

Use of spider silk fibres as an innovative material in a biocompatible artificial nerve conduit

Defects of peripheral nerves still represent a challenge for surgical nerve reconstruction. Recent studies concentrated on replacement by artificial nerve conduits from different synthetic or biological materials. In our study, we describe for the first time the use of spider silk fibres as a new material in nerve tissue engineering. Schwann cells (SC) were cultivated on spider silk fibres. Cells adhered quickly on the fibres compared to polydioxanone monofilaments (PDS). SC survival and proliferation was normal in Live/Dead assays. The silk fibres were ensheathed completely with cells. We developed composite nerve grafts of acellularized veins, spider silk fibres and SC diluted in matrigel. These artificial nerve grafts could be cultivated in vitro for one week. Histological analysis showed that the cells were vital and formed distinct columns along the silk fibres. In conclusion, our results show that artificial nerve grafts can be constructed successfully from spider silk, acellularized veins and SC mixed with matrigel.     

Photobiomodulation at a wavelength of 633 nm leads to faster functional recovery than 804 nm after facial nerve injury

We analyzed the effects of photobiomodulation (PBM) of various wavelengths on regeneration of the facial nerve using in vitro and in vivo experimental models. We assessed the antioxidative effect of PBM in geniculate ganglion neurons irradiated with a diode laser at 633 nm, 780 nm and 804 nm. Wavelengths of 633 and 780 nm but not 804 nm inhibited cell death by oxidative stress. We assessed the effects of PBM on functional and morphologic recovery in rats divided into control, facial nerve damage (FND) and FND irradiated with a 633 nm or 804 nm lasers. Injured rats treated with 633-nm light had better facial palsy scores, larger axon diameter and higher expression of Schwann cells compared with the FND group. No positive results were observed in rats irradiated at 804-nm light. These findings indicate that 633-nm PBM promotes accelerated nerve regeneration and improved functional recovery in an injured facial nerve.