Physiological properties of neurons in the mouse superior olive: membrane characteristics and postsynaptic responses studied in vitro.
Physiological properties of neurons in the mouse superior olive: membrane characteristics and postsynaptic responses studied in vitro.
复制标题
小鼠上橄榄神经元的生理特性：体外研究的膜特征和突触后反应。
DOI：
10.1152/jn.1991.65.2.230
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发表时间：
1991
影响因子：
2.5
通讯作者：
J. Kelly
中科院分区：
文献类型：
--
作者：
S. Wu;J. Kelly
1. 通过小鼠听觉脑干获取的 400 微米脑切片研究了上橄榄复合体 (SOC) 中细胞的生理特性。从新鲜脑组织制备冠状切片并将其完全浸没在含氧盐水溶液中。通过解剖显微镜观察梯形体内侧核 (MNTB)、外侧上橄榄核 (LSO) 和梯形体纤维的边界，并将装有 4 M 醋酸钾的微量移液器插入 LSO 或 MNTB。 2. 双极刺激电极沿着梯形体放置，通常位于中线交叉处和 LSO 的侧面位置。这种布置允许刺激 SOC 对侧和同侧的梯形体。通过向梯形体的纤维传递短暂（0.1 毫秒）电流脉冲来引发突触电位。在某些情况下，在沿通路的不同位置进行细胞外显微注射后，通过辣根过氧化物酶（HRP）的转运来证实纤维的完整性。 HRP 反应产物揭示了梯形体内的主动运输以及 MNTB 和 LSO 中的特征性突触和末端形态。 MNTB 主要包含终止于特殊末端（Held 的肾盏）的大直径纤维，而 LSO 主要包含小直径纤维和点状末端纽扣。 3.通过向细胞中注入电流并测量相应的电压变化来确定MNTB和LSO中细胞的膜特性。 LSO 中的神经元在电压和细胞内注入电流之间表现出大致线性关系。负电流导致细胞膜分级超极化，正电流导致分级去极化，从而产生动作电位。动作电位的数量与注入电流的强度直接相关。相比之下，MNTB 中的神经元的电流-电压关系在静息电位附近呈强烈非线性关系。负电流的注入导致分级超极化，但正电流的注入产生有限的去极化，从而导致单个大动作电位或动作电位随后出现几个幅度大大降低的尖峰。 4. LSO 中梯形体的同侧刺激可引起兴奋性突触后电位 (EPSP)，而 MNTB 中的对侧刺激可引起兴奋性突触后电位 (EPSP)。为了响应重复刺激，LSO 中的一些细胞表现出时间求和，即一系列略低于阈值的电流脉冲产生突触后电位，这些突触后电位结合起来引发动作电位。（摘要截断为 400 字）
1. The physiological properties of cells in the superior olivary complex (SOC) were studied in 400-microns brain slices taken through the mouse auditory brain stem. Coronal sections were prepared from fresh brain tissue and were placed fully submerged in an oxygenated saline solution. The boundaries of the medial nucleus of the trapezoid body (MNTB), the lateral superior olive (LSO), and the fibers of the trapezoid body were visualized through a dissecting microscope, and micropipettes filled with 4 M potassium acetate were inserted into the LSO or MNTB. 2. Bipolar stimulating electrodes were placed along the trapezoid body usually at the midline decussation and at a location just lateral to the LSO. This arrangement allowed for stimulation of the trapezoid body both contralateral and ipsilateral to the SOC. Synaptic potentials were elicited by delivering brief (0.1 ms) current pulses to the fibers of the trapezoid body. In some cases the integrity of the fibers was confirmed by transport of horseradish peroxidase (HRP) after extracellular microinjections at various locations along the pathway. The HRP reaction product revealed active transport within the trapezoid body and characteristic synaptic and terminal morphology in the MNTB and LSO. The MNTB contained primarily large-diameter fibers terminating in specialized endings (the calyces of Held), whereas the LSO contained mainly small-diameter fibers and punctate terminal boutons. 3. Membrane characteristics of cells in MNTB and LSO were determined by injecting current into the cell and measuring the corresponding voltage change. Neurons in LSO exhibited a roughly linear relation between voltage and intracellularly injected current. Negative current resulted in a graded hyperpolarization of the cell membrane, and positive current resulted in a graded depolarization that led to the production of action potentials. The number of action potentials was directly related to the strength of the current injected. In contrast, the neurons in MNTB had current-voltage relations that were strongly nonlinear around resting potential. The injection of negative current led to graded hyperpolarization, but injection of positive current produced a limited depolarization that resulted in either a single large action potential or an action potential followed by several spikes with greatly reduced amplitude. 4. Excitatory postsynaptic potentials (EPSPs) could be elicited in LSO by ipsilateral stimulation of the trapezoid body and in MNTB by contralateral stimulation. In response to repeated stimulation, some cells in LSO exhibited temporal summation, that is, a series of slightly subthreshold current pulses produced postsynaptic potentials that combined to elicit action potentials.(ABSTRACT TRUNCATED AT 400 WORDS)