Dendritic growth and changes in electrophysiological properties during development of chick vestibular neurons.
Dendritic growth and changes in electrophysiological properties during development of chick vestibular neurons.
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雏鸡前庭神经元发育过程中的树突生长和电生理特性的变化。
DOI：
10.1111/j.1749-6632.1996.tb15757.x
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发表时间：
1996
影响因子：
5.2
通讯作者：
Giaume,C
中科院分区：
文献类型：
--
作者：
Peusner,KD;Giaume,C
前庭感觉神经元是第一个将来自前庭终末器官的信号传递到控制眼球运动和颈部肌肉组织的运动神经元的脑元件。这种基本的前庭反射在脊椎动物的发育过程中是高度保守的。“尽管小鸡前庭系统包含标准的前庭回路，但它也为研究神经元生理学的发展提供了几个优势。2鸟类的切向核（TN）被认为是延髓外侧前庭复合体的一部分。主细胞（PC）人口的这个核（80%的总数）是由神经元的轴突可能在对侧内侧纵束分叉，然后支配眼和颈脊髓运动神经元。这项工作的重点是相关的形态和电生理个体发育的PC。从13天（E13）、15至16天（E15-16）阶段的鸡胚以及1至2天（H1 -2）孵化的幼雏制备脑切片。细胞内记录和注射是在界面型记录室（30-31 ℃）中孵育的切片（350-500 km厚）上进行的，并用标准盐水溶液灌注。细胞内微电极在2 M乙酸钾中含有1.5%的生物胞素，电阻为150至200 Ma。将含有生物胞素注射的细胞的切片固定，以100 km的厚度切除，并进行免疫细胞化学反应以使染色可视化，然后使用连接到光学显微镜的照相机透明绘图管重建其形态。在所研究的三个阶段中，典型的PC椭圆形胞体的大小是恒定的（= 27 f1 × 17 f2 km，n= 32，mf SEM），而树突生长出来。在E13，树突开始从被细突起或丝状伪足覆盖的胞体形成，向各个方向辐射（图1A 1）。在E15-16，树突继续主要在平行于初级前庭传入的内侧和外侧方向上生长（图1B 1）。与E15-16相比，到H1-2，树突的总长度增加，主要是通过在背腹轴上延伸（图1C 1）。当比较三个阶段的PC的电特性时，静息膜电位平均为-60 mV，而输入电阻从
Vestibular sensory neurons are the first brain elements that relay signals originating from vestibular end-organs to influence the motor neurons controlling eye movements and neck musculature. This basic vestibular reflex is highly conserved during vertebrate phylogeny.'Whereas the chick vestibular system contains the standard vestibular circuitry, it also offers several advantages to investigate development of neuronal physiology. 2 In avians the tangential nucleus (TN) is considered to be part of the lateral vestibular complex in the medulla. The principal cell (PC) population of this nucleus (80% of total) is composed of neurons whose axons may bifurcate in the contralateral medial longitudinal fasciculus and then innervate both oculomotor and cervical spinal cord motor neurons. The focus of this work is to correlate the morphological and electrophysiological ontogeny of PCs. Brain slices were prepared from chick embryos staged at 13 days (E13), 15 to 16 days (E15-16), and also from hatchlings of 1 to 2 days (Hl-2). Intracellular recordings and injections were performed on slices (350-500 km thickness) incubated in an interface-type recording chamber (30-31 C) and perfused with standard saline s~ lution.~ Intracellular microelectrodes contained 1.5% biocytin in 2M potassium acetate and had resistances of 150 to 200 Ma. Slices containing biocytininjected cells were fixed, resectioned at 100-km thickness, and reacted immunocytochemically to visualize staining before reconstructing their morphology using a camera lucida drawing tube attached to a light microscope. At the three stages studied, the typical PC oval somata are constant in size (= 27 f 1 X 17 f 2 km, n= 32, m f SEM) while the dendrites grow out. At E13, dendrites are beginning to form from somata covered by thin processes or filopodia that radiate in all directions (FIG. lAl). At E15-16 the dendrites continue to grow mainly in the medial and lateral directions parallel to the primary vestibular afferents (FIG. lB1). By H1-2 the dendrites have increased in total length as compared to E15-16, mostly by extending in the dorsoventral axis (FIG. lC1). When comparing electrical properties of PCs at the three stages, the resting membrane potentials averaged-60 mV, while input resistanccs decreased from