果蝇中枢神经元受体的离子通道电生理学研究进展

果蝇这个良好的实验材料使我们能将遗传学、分子生物学和电生理学等各种方法有机地结合起来,从而为研究无脊椎乃至脊椎动物神经元的信号转导、神经网络的信息加工及中枢神经系统活动规律等提供了一条捷径。自20世纪70年代以来,很多研究都致力于果蝇基因的克隆和DNA测序工作。然而,新近果蝇基因组序列测定的完成标志着对果蝇的研究已进入了后基因组时代,通过直接的生理学特别是电生理学方法去研究果蝇基因的生物学功能已成为当前的主要任务。本文综述果蝇中枢神经元受体和离子通道电生理学研究进展。     

离子通道受体p2X7的研究进展

一、p2x，受体的发展史 1929年Druryt-Gyortyi首次发现静脉注射腺苷后可引起豚鼠心动过缓、尿分泌抑制和血管舒张等现象，同年Lohmann等发现ATP分子；1953年，Hollton等发现神经末梢可以释放ATP，随后ATP作为一种神经递质逐渐被揭示。1972年Burnstock提出了嘌呤能神经学说，1978年被正式命名嘌呤受体，     

情感性障碍的电生理学研究进展

随着科学发展,近年已形成精神电生理学这一门新的学科。本文就近年来欧美在这方面的一些工具研究进展及未来方向作一介绍。 一、研究工具 (一)自发脑电 1.常规脑电图(EEG):1978年之前只有少数的EEG研究,且曾一度静寂。2.药物脑电图(PEEG):PEEG是一种观察精神药物对中枢神经系统影响的最简单的方法。3.睡眠脑电图(SEEG):又称多导睡眠图(PSG)。SEEG技术对睡眠的研究具有决定性意义。该技术发现睡眠是由伴有快速眼球运动(REM)的和不伴有快速眼球运动(NREM)的两种不同的周期性时相所组成。     

乙酰胆碱受体抗体与大鼠中枢神经元烟碱型乙酰胆碱受体之间免疫结合反应

本研究旨在探讨长期以来无定论的重症肌无力（MG）患者血和脑脊液（CSF）中的乙酰胆碱受体抗体（AChRab）能否与中枢神经元烟碱型乙酰胆碱受体（神经-nAChR）结合，并引起中枢神经系统（CNS）功能障碍。用免疫亲和层析法从AChRab阳性的全身型MG患者血中提取纯化AChRab，然后用免疫组化法探讨AChRab与大鼠中枢神经-nAChR之间的免疫结合反应。结果首次表明，AChRab与神经-nAChR之间的阳性免疫结合反应广泛分布于大鼠大脑皮层、脑干颅神经运动核团、脊髓前角运动神经元等部位，提示MG患者AChRab不仅可与神经肌接头（NMJ）处肌-nAChR结合引起肌无力等症状，还可与CNS神经-nAChR结合，并可能引起CNS功能障碍。     

乙酰胆碱受体抗体与大鼠中枢神经元烟碱型乙酰…

本研究旨在探讨长期以来无定论的重症肌无力患者血和脑脊液中的乙酰胆碱受体抗体能否与中枢神经元烟碱型乙酰胆碱受体结合并引起中枢神经系统功能障碍。用免疫亲和层析法从ＡＣｈＲａｂ阳性的全身型ＭＧ患者血中提取纯化ＡＣｈＲａｂ，然后用免疫组化法探讨ＡＣｈＲａｂ与大鼠中枢神经ｎＡＣｈＲ之间的免疫结合反应。     

伏膈核神经元的分型及其形态和生理学特征

伏膈核（NAC）是腹侧纹状体的重要组成部分，接受边缘系统和锥体外运动系统的纤维输入，整合后主要输出至腹侧苍白球，在行为，动机，奖赏尤其是毒品成瘾和神经精神性疾病中的作用近年来受到高度重视，依形态和生理学特性可以将NAC内的神经元大致分为4型，约95％的神经元为MS投射神经元，约5％为中间神经元，它们共同调控伏膈核的功能活动。     

发作性共济失调与离子通道病的研究进展

发作性共济失调(episodic ataxia，EA)是一类少见的常染色体显性遗传病，主要表现为自限性小脑功能障碍几乎不伴固定的或进行性神经功能异常。自1946年Parker首先报道了11例发作性共济失调的患者以来，许多学者相继发现了类似家系，并对他们进行了描述。近年来，家族基因连锁分析及电生理学研究发现此类疾病是由编码离子通道的基因突变造成。     

伏膈核神经元的分型及其形态和生理学特征

伏膈核 (NAC)是腹侧纹状体的重要组成部分 ,接受边缘系统和锥体外运动系统的纤维输入 ,整合后主要输出至腹侧苍白球 ,在行为、动机、奖赏尤其是毒品成瘾和神经精神性疾病中的作用近年来受到高度重视。依形态和生理学特性可以将 NAC内的神经元大致分为 4型 ,约95 %的神经元为 MS投射神经元 ,约 5 %为中间神经元 ,它们共同调控伏膈核的功能活动     

愤怒与攻击行为的脑电生理学研究进展

近年来攻击行为的发生率不断上升,导致暴力犯罪率逐年增长,引起了国内外各界的关注.目前,对人类攻击性行为的研究一般集中在生物、社会环境和认知因素三个方面,本文主要从心理学相关因素--愤怒的角度对攻击行为进行阐述.大量研究表明:攻击与暴力是情绪失调的结果,个体越是对负性情绪调节不完善,越是具有攻击与暴力的危险.本文就愤怒与攻击行为的基础生理学及脑电生理学研究进展进行综述.     

Ligand-gated ion channels in the enteric nervous system

There are many cell surface receptors expressed by neurones in the enteric nervous system (ENS). These receptors respond to synaptically released neurotransmitters, circulating hormones and locally released substances. Cell surface receptors are also targets for many therapeutically used drugs. This review will focus on ligand-gated ion channels, i.e. receptors in which the ligand binding site and the ion channel are parts of a single multimeric receptor. Ligand-gated ion channels expressed by enteric nerves are: nicotinic acetylcholine receptors (nAChRs), P2X receptors, 5-hydroxytryptamine3 (5-HT3) receptors, gamma-aminobutyric acid (GABAA) receptors, N-methyl-d-aspartate (NMDA) receptors,alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors and glycine receptors. P2X, 5-HT3 and nAChRs participate in fast synaptic transmission in S-type neurones in the ENS. Fast synaptic transmission occurs in some AH-type neurones, and AH neurones express all the ligand-gated ion channels listed above. Ligand-gated ion channels may be localized at extra-synaptic sites in some AH neurones and these extra-synaptic receptors may be useful targets for drugs that can be used to treat disorders of gastrointestinal function.     

Characterization of neurons in the rat central nucleus of the amygdala: cellular physiology, morphology, and opioid sensitivity

The central nucleus of the amygdala (CeA) orchestrates autonomic and other behavioral and physiological responses to conditioned stimuli that are aversive or elicit fear. As a related CeA function is the expression of hypoalgesia induced by conditioned stimuli or systemic morphine administration, we examined postsynaptic opioid modulation of neurons in each major CeA subdivision. Following electrophysiological recording, biocytin-filled neurons were precisely located in CeA regions identified by chemoarchitecture (enkephalin-immunoreactivity) and cytoarchitecture (DAPI nuclear staining) in fixed adult rat brain slices. This revealed a striking distribution of physiological types, as 92% of neurons in capsular CeA were classified as late-firing, whereas no neurons in the medial CeA were of this class. In contrast, 60% or more of neurons in the lateral and medial CeA were low-threshold bursting neurons. Mu-opioid receptor (MOPR) agonists induced postsynaptic inhibitory potassium currents in 61% of CeA cells, and this ratio was maintained in each subdivision and for each physiological class of neuron. However, MOPR agonists more frequently inhibited bipolar/fusiform cells than triangular or multipolar neurons. A subpopulation of MOPR-expressing neurons were also inhibited by delta opioid receptor agonists, whereas a separate population were inhibited kappa opioid receptors (KOPR). The MOPR agonist DAMGO inhibited 9/9 CeM neurons with projections to the parabrachial nucleus identified by retrograde tracer injection. These data support models of striatopallidal organization that have identified striatal-like and pallidal-like CeA regions. Opioids can directly inhibit output from each subdivision by activating postsynaptic MOPRs or KOPRs on distinct subpopulations of opioid-sensitive neurons.     

缺氧对大鼠大脑皮层神经元钙激活性钾通道的影响

目的　研究缺氧对大鼠大脑皮层神经元钙激活性钾 (Kca)通道的影响 ,以揭示神经元抗缺血损伤的电生理机制。方法　在不同缺氧条件下 ,应用膜片钳技术记录大脑皮层神经元上Kca通道电流活动。电流信号经放大、滤波及A/D、D/A转换后输入微机进行采样和储存。实验数据应用PClamp(6 .0 .2 )软件进行分析处理。结果　缺氧对通道的开放概率 (Po)及平均开放时间 (To)有明显影响 ,在缺氧实验早期通道Po明显增加 ,其中 10 μmol·L-1NaCN缺氧组其增加程度大于 2 0 μmol·L-1和 30 μmol·L-1NaCN缺氧组 (P <0 .0 5 )。而在缺氧实验后期通道Po和To明显降低 ,其中 30 μmol·L-1NaCN缺氧组其降低程度大于 2 0 μmol·L-1和 10 μmol·L-1NaCN缺氧组 (P <0 .0 5 )。结论　缺氧早期大脑皮层神经元Kca通道激活 ,产生超极化电位 ,从而稳定细胞膜 ,降低细胞兴奋性 ,延缓缺氧除极的发生 ,这可能是神经元自身的一种代偿作用     

快速老化小鼠海马神经元电压门控离子通道特点

目的：观察快速老化小鼠（Senescence-accelerated mouse,SAM)海马神经元的基本离子通道特点，并对抗快速老化亚系（SAM－resistance/1,SAMR1)与快速老化亚系（SAM－prone/8,SMAP8)的基本离子通道特点进行了比较，探讨了离子通道变化在衰老中的可能角度，方法：应用全细胞记录方式，观察并比较原代培养SAMR1和SAMP8海马神经元的电压门控离子通道及膜参数。结果：原代培养SAMR1和SAMP8海马神经元电压门控Na^2 通道电流（INa)和电压门控延迟整流K^ 通道电流（IK）的电学特点和幅度基本一致。SAMP8的电压门控Ca^2 通道电流（ICa)和瞬时外向K^ 通道电流（IA）的幅值则大于相同培养天数的SAMR1。经膜电容校正所得的ICa电流密度也表现出增大的变化规律。结论：SAMP8与SAMR1神经元间IA和ICa的差异可能与其神经系统变异而产生的学习记忆功能下降有关。     

Orexin A depolarises rat intergeniculate leaflet neurons through non‐selective cation channels

Orexins/hypocretins are hypothalamic neuropeptides that have a variety of functions, including maintenance of arousal, control over the sleep/wake cycle, reward and feeding. Accumulating evidence links orexins to the time‐keeping system with a documented action in the master clock—the suprachiasmatic nucleus. The intergeniculate leaflet (IGL) is a thalamic structure with the well‐known function of collecting photic and non‐photic cues to adjust the rhythm of the suprachiasmatic nucleus to changing environmental conditions. The IGL consists of GABAergic neurons that are intrinsically active, even in slice preparations. Our previous studies revealed the excitatory postsynaptic effects of orexins on single IGL neurons, even though the ionic mechanism underlying this effect remained elusive. Therefore, in this study, we used patch clamp electrophysiology to identify the ions and distinct ion channels responsible for the observed depolarisations. The major finding of this article is that the orexin A‐evoked depolarisation of IGL neurons depends on non‐selective cation channels, implicating the orexinergic tone in establishing the basal firing rate in these cells. The data presented here strengthen the mutual connections between the time‐keeping and orexinergic systems.     

酮体抑制大鼠海马神经元酸敏感通道的开放

目的 探讨酮体对酸敏感通道的影响。方法 原代培养大鼠海马神经元,利用膜片钳技术检测乙酰乙酸、β羟丁酸和丙酮三种酮体对海马神经元酸敏感通道开放状态的影响。结果 在pH6.0条件下细胞外液中分别加入乙酰乙酸、β羟丁酸和丙酮,酸敏感通道电流均明显减弱。三种酮体均可显著抑制海马神经元表面酸敏感通道的开放,抑制率分别为92、47和77%。结论 酮体可以显著抑制酸敏感通道的开放。生酮饮食治疗难治性癫痫有可能是通过酮体抑制酸敏感通道来实现。     

Mechanotransducing ion channels in C6 glioma cells

Mechanotransducing (MS) ion channels and images of the patch membrane were studied in cell-attached patches in C6 glioma cells. MS channel density was ∼0.08 to 0.5 channels/μm², channel conductance was ∼40 pS (at -40 mV), and the reversal potential was +15 mV. Replacement of NaCl with KCl, CsCl, or Na gluconate in the pipette solution was without substantial effect on the current-voltage relationship. Replacement of NaCl with NMDG (N-Methyl-D-Glucamine) Cl or reducing NaCl decreased the amplitude of inward currents at negative membrane potentials and caused the reversal potential to shift in the negative direction. Rapid application of suction to the back of the pipette usually elicited a fast (<0.1 s) appearance of channel activity. The peak (phasic) in channel activity was followed by a decrease to a constant (tonic) level of activity. The reduction in channel activity—called adaptation—was reduced at depolarizing membrane potentials and disappeared if too much pressure was applied. Positive pressure caused the patch membrane to curve toward the pipette tip, move in the direction of the tip, and evoke MS channel activity. Removal of the positive pressure caused the patch to move back to the original position. Conversely, negative pressure caused the patch membrane to curve away from the pipette tip, move away from the tip, and elicit MS channel activity. Gigohm seal resistances were always maintained during translational movement of the patch membrane. Tonic MS channel activity was not associated with translational movements of the patch membrane. Phasic and tonic channel activity were independent of the sign of curvature of the patch membrane. C6 glioma cells have rapidly adapting voltage-dependent MS ion channels, which are non-selective for monovalent cations, and belong to the stretch-activating class of mechanosensory ion channels. Adaptation in MS channels may allow the cell to limit the influx of cations in response to mechanical input. The selective loss of adaptation suggests that the MS channel's gate receives input from two sources. A minimal viscoelastic mechanical model of adaptation and two alternative models for translational movement of the patch are presented. © 1996 Wiley-Liss, Inc.     

Pontomedullary raphe neurons: Intracellular responses to central and peripheral electrical stimulation

The responses of pontomedullary raphe neurons to electrical stimulation of the medullary reticular formation (MRF) and the mesencephalic ventral periaqueductal gray region (PAG) were studied using intracellular methods in chloralose-anesthetized cats. Single shock stimulation of PAG at the level of the trochelear nucleus evoked short latency, monosynaptic excitatory postsynaptic potentials (EPSPs) in antidromically identified raphe-spinal neurons. Similar large EPSPs were produced by medullary reticular stimulation of either side. The large majority of raphe-spinal neurons responded to sciatic nerve shock, and most responded to tooth pulp or forepaw shock as well; these responses were always bilateral. The responses of cells that could not be antidromically invaded from spinal cord were similar to those of raphe-spinal neurons, but tended to be more variable. Intracellular injection of horseradish peroxidase into electrophysiologically characterized cells revealed that most recordings were made from large and medium sized raphe neurons. These findings are discussed in the context of a potential role for pontomedullary raphe neurons in nociception.     

Sequential acquisition of cacophony calcium currents,sodium channels and voltage‐dependent potassium currents affects spike shape and dendrite growth during postembryonic maturation of an identified Drosophila motoneuron

During metamorphosis the CNS undergoes profound changes to accommodate the switch from larval to adult behaviors. In Drosophila and other holometabolous insects, adult neurons differentiate either from respecified larval neurons, newly born neurons, or are born embryonically but remain developmentally arrested until differentiation during pupal life. This study addresses the latter in the identified Drosophila flight motoneuron 5. In situ patch‐clamp recordings, intracellular dye fills and immunocytochemistry address the interplay between dendritic shape, excitability and ionic current development. During pupal life, changes in excitability and spike shape correspond to a stereotyped, progressive appearance of voltage‐gated ion channels. High‐voltage‐activated calcium current is the first current to appear at pupal stage P4, prior to the onset of dendrite growth. This is followed by voltage‐gated sodium as well as transient potassium channel expression, when first dendrites grow, and sodium‐dependent action potentials can be evoked by somatic current injection. Sustained potassium current appears later than transient potassium current. During the early stages of rapid dendritic growth, sodium‐dependent action potentials are broadened by a calcium component. Narrowing of spike shape coincides with sequential increases in transient and sustained potassium currents during stages when dendritic growth ceases. Targeted RNAi knockdown of pupal calcium current significantly reduces dendritic growth. These data indicate that the stereotyped sequential acquisition of different voltage‐gated ion channels affects spike shape and excitability such that activity‐dependent calcium influx serves as a partner of genetic programs during critical stages of motoneuron dendrite growth.