异位电活动促使背根神经节交感节后纤维的芽生

在慢性压迫性损伤(CCI)大鼠模型上分别全身性给予K+离子通道阻断剂4-氨基吡啶(4-AP)或M受体阻断剂山莨菪碱制造高频的异位放电或异位放电被抑制的背景, 观察CCI动物的热痛过敏和DRG内交感节后纤维末梢芽生的改变. 发现神经损伤后4-AP诱发高频的异位电活动可促使DRG内大量的交感节后纤维芽生并形成大量的交感腺素能的篮状细胞, 动物的热痛过敏加剧; 而在山莨菪碱抑制异位放电的背景下, DRG内交感纤维的芽生明显减少, 动物的热痛过敏减轻. 提示神经损伤后产生的异位电活动可能是DRG交感纤维芽生的直接因素.     

线粒体介导的能量代谢对中枢神经损伤修复的作用研究进展

线粒体介导的能量代谢与中枢神经损伤修复关系密切。中枢神经损伤会导致线粒体损伤、线粒体运输变弱、局部线粒体去极化以及ATP损失,引起轴突局部能量缺乏。因此,健康线粒体数量的保证及其运输和定位的有效调节对于满足中枢神经损伤修复所需要的能量至关重要。该文综述了中枢神经损伤后,神经细胞的能量需求及线粒体动态变化,分析了线粒体功能与中枢神经损伤修复的关系,并归纳了线粒体相关的促进神经系统损伤修复策略的相关研究进展,旨在通过该综述为临床上促进中枢神经损伤修复提供新的思路。     

鸣禽锡嘴雀(Coccothraustes coccothraustes)发声中枢的定位研究

用常规组织学,HRP 逆行示踪,电生理等方法确定了鸣禽锡嘴雀控制发声的神经核团及这些核团的定位坐标值。锡嘴雀控制发声的神经通路由四级神经核团组成。位于端脑上纹状体腹侧的尾部区域(HVc)是控制鸣禽发声的高位中枢,它发出的神经纤维投射到端脑原纹状体腹内侧的粗核(RA),由 RA 又发出两束纤维,分別投射到中脑丘间核(ICo)和延脑的中间核(IM)。左右侧发声控制神经通路并非严格单侧性,每侧气管鸣管肌群分別受双侧发声中枢的交叉控制。中脑 ICo 在控制发声行为中具有相对独立性。各级发声核团的定位坐标值为,HVc∶p1.3,L/R2.4,H0.8;RA∶1.4,L/R3.2,H6.0;ICo∶p0.3,L/R2.6,H8.5:IM∶P3.1,L/R1.0,H∶7.8。     

院内一体化急救护理干预对急性缺血性脑卒中静脉溶栓患者预后的影响

目的 探讨院内一体化急救护理干预对急性缺血性脑卒中静脉溶栓患者的影响.方法 选择2019年1月 ～2020年1月在我院接受阿替普酶静脉溶栓治疗的190例急性缺血性脑卒中患者作为研究对象,将其分为对照组100例,观察组90例.对照组采用常规护理措施,观察组采用院内一体化急救护理干预措施,观察比较两组患者护理前和护理后第7...     

A GIM-Based Biomimetic Learning Approach for Motion Generation of a Multi-Joint Robotic Fish

In this paper, we propose a biomimetic learning approach for motion generation of a multi-joint robotic fish. Based on a multi-joint robotic fish model, two basic Carangiform swimming patterns, namely ＂cruise＂ and ＂C sharp turning＂, are extracted as training samples from the observations of real fish swimming. A General Internal Model （GIM）, which is an imitation of Central Pattern Generator （CPG） in nerve systems, is adopted to learn and to regenerate coordinated fish behaviors. By virtue of the universal function approximation ability and the temporal/spatial scalabilities of GIM, the proposed learning approach is able to generate the same or similar fish swimming patterns by tuning two parameters. The learned swimming patterns are implemented on a multi-joint robotic fish in experiments. The experiment results verify the effectiveness of the biomimetic learning approach in generating and modifying locomotion patterns for the robotic fish.     

On-line Optimization of Biomimetic Undulatory Swimming by an Experiment-based Approach

An experiment-based approach is proposed to improve the performance of biomimetic undulatory locomotion through on-line optimization. The approach is implemented through two steps： （1） the generation of coordinated swimming gaits by artificial Central Pattern Generators （CPGs）; （2） an on-line searching of optimal parameter sets for the CPG model using Genetic Algorithm （GA）. The effectiveness of the approach is demonstrated in the optimization of swimming speed and energy effi- ciency for a biomimetic fin propulsor. To evaluate how well the input energy is converted into the kinetic energy of the pro- pulsor, an energy-efficiency index is presented and utilized as a feedback to regulate the on-line searching with a closed-loop swimming control. Experiments were conducted on propulsor prototypes with different fin segments and the optimal swimming patterns were found separately. Comparisons of results show that the optimal curvature of undulatory propulsor, which might have different shapes depending on the actual prototype design and control scheme. It is also found that the propulsor with six fin segments, is preferable because of hizher speed and lower energy efficiency.     

家兔主动脉神经高阈压力感受反射性速重调中枢过程的机能特征

Experiments were performed on 37 urethane-anesthetized rabbits. The aortic nerves, carotid sinus nerves and vagus nerves were cut, MAP and renal sympathetic nerve activity (RSNA) were recorded. The conditional stimulation CSc (0.5 ms, 10 Hz, 4-6V, 5 min) was used to mimic the information of baroreflex non-medullated afferent fibers responding to acute increase of BP. Test stimulation TSa (0.02 ms, 0-80 Hz/30 s, 4-6V) and TSc (0.5 ms, 0-20 Hz/30s, 4-6V) was used to examine the responses of baroreflex A- and C-fibers. After CSc at 1 min the reflex MAP and RSNA of TSc was attenuated at 45.5% (P less than 0.01) and 10.6% (P less than 0.05), the MAP response of TSa was attenuated at 32.1% (P less than 0.05), but the RSNA response was not. From the further investigation it is concluded that the characteristics of central acute resetting are dependent on the components of baroreflex afferent fibers. The reflex responses are attenuated mainly by correspondent afferent components.     

大鼠前庭内侧核在前庭—交感反应中的作用

实验在氯醛糖和尿酯混合麻醉的大鼠上进行。在内脏大神经上记录刺激同侧前庭神经进入脑干处的交感反应。电刺激前庭神经可在同侧内脏大神经引出—明确的叠加反应,其平均潜伏期为45.8±6.98ms,时程为55.21±5.35ms。增加刺激强度,反应幅度也增加,但潜伏期不变。用前庭内侧核(NVM)的片层场电位作为指标并选择其相位倒转处作刺激点,可在同侧内脏大神经记录到潜伏期为32ms 的叠加反应,而同一动物刺激前庭神经入脑处时内脏大神经反应的潜伏期为43ms。在 NVM 头端损毁后,此前庭-交感反应明显减小,再损毁尾端 NVM 后,此反应消失。损毁 Deiters 核对前庭-交感反应无影响。这些结果表明 NVM在内脏大神经记录到的前庭-交感反应中是一重要的中继站。     

硝普钠造成犬低血压时电针升压作用的机制分析

本工作观察到给清醒犬静脉内匀速注射扩血管药硝普钠可造成稳定的急性实验性低血压,电针相当于“足三里”或“内关”穴部位对此实验性低血压具有显著的升压作用,而对心率和呼吸频率无明显影响。在麻醉动物身上,电针对此类实验性低血压仍可产生显著的升压作用。电针产生升压作用时,心输出量增加,肾血流量减少,而肠系膜上动脉及股动脉血流量变化不显著。还观察到电针可使实验性低血压部分的血压-心率曲线右移,斜率增大。实验性低血压时,静脉注射纳洛酮不能阻断电针的升压作用,而注射阿托品或东茛菪碱后给予电针不再出现升压效应。实验结果表明:电针对舒血管药物造成的急性实验性低血压具有明显的升压作用,此升压作用仍可在麻醉动物身上产生,并与电针时中枢内胆碱能系统的激活有关,而心输出量增加和肾血流量减少在电针升压效应中起一定作用。