CHARACTERIZATION OF IDENTIFIABLE NEURONS IN THE HEAD GANGLIA OF THE PARASITIC NEMATODE ASCARIS-SUUM - A COMPARISON WITH CENTRAL NEURONS OF CAENORHABDITIS-ELEGANS
CHARACTERIZATION OF IDENTIFIABLE NEURONS IN THE HEAD GANGLIA OF THE PARASITIC NEMATODE ASCARIS-SUUM - A COMPARISON WITH CENTRAL NEURONS OF CAENORHABDITIS-ELEGANS
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DOI：
10.1017/s0031182000078550
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发表时间：
1994-01-01
期刊：
影响因子：
2.4
通讯作者：
WALKER, RJ
中科院分区：
文献类型：
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作者：
HOLDENDYE, L;WALKER, RJ
已经用蛔虫头部神经节的神经元进行了细胞内记录。这些神经元的静息膜电位较低，为-21+/-9 mV(n=78)，而输入电阻相对较高(例如，100微米细胞的输入电阻为25M欧姆)。在所有情况下，通过注射荧光标记物5，6-羧基荧光素(CBXF)来验证记录电极的细胞内位置。为了确定低膜电位是否是由于穿孔损伤，使用两个微电极记录了同一神经元。用20M欧姆3M氯化钾电极第一次注入膜电位为-38 mV，用80M欧姆CBXF电极第二次注入后膜电位降至-34 mV。使用单电极和双电极细胞内记录技术来估计这些单元的输入电阻，并且在两种情况下都产生相对较高的单元大小的值(例如，对于100微米单元，25M欧姆)。细胞内注射5，6-羧基荧光素标记的神经元形态简单，缺乏广泛的分支。背神经节是一个仅由3个神经元组成的离散结构。在这里，我们将这些神经元的形态特征与秀丽线虫背神经节中所描述的那些进行了比较。因此，蛔虫神经节的整装制备为研究线虫中枢神经系统神经元的功能特性提供了一个有用的模型，并为评估驱虫药的中枢作用部位提供了可能性。
Intracellular recordings have been made from neurones in the head ganglia of Ascaris. The neurones had low resting membrane potentials of -21+/-9 mV (n = 78) and a relatively high input resistance (e.g. 25 M Ohm for a 100 mu m cell). In all cases the intracellular location of the recording electrode was verified by injection of the fluorescent marker, 5,6-carboxyfluorescein (CBXF). To ascertain whether or not the low membrane potential was due to impalement damage, the same neurone was recorded from using two microelectrodes. The membrane potential following the first impalement by a 20 M Ohm 3 M KCl electrode was -38 mV and following the second impalement by a 80 M Ohm CBXF (for subsequent intracellular labelling) electrode was decreased to -34 mV. Input resistance of these cells was estimated using both single and two electrode intracellular recording techniques and in both cases yielded a relatively high value for the size of cell (e.g. 25 M Ohm for a 100 mu m cell). Neurones labelled by intracellular injection of the fluorescent marker 5,6-carboxyfluorescein were morphologically simple and lacked extensive arborizations. The dorsal ganglion is a discrete structure consisting of only 3 neurones. Here we compare the morphological properties of these neurones to those described in the dorsal ganglion of Caenorhabditis elegans. The whole mount preparation of Ascaris ganglia thus provides a useful model to study the functional properties of neurones in nematode central nervous system and presents the possibility to assess central sites of action for anthelmintics.