INTRACELLULAR TETRAETHYLAMMONIUM IONS ENHANCE GROUP IA EXCITATORY POSTSYNAPTIC POTENTIALS-EVOKED IN CAT MOTONEURONS
INTRACELLULAR TETRAETHYLAMMONIUM IONS ENHANCE GROUP IA EXCITATORY POSTSYNAPTIC POTENTIALS-EVOKED IN CAT MOTONEURONS
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DOI：
10.1113/jphysiol.1986.sp016186
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发表时间：
1986-08-01
影响因子：
5.5
通讯作者：
REDMAN, SJ
中科院分区：
文献类型：
--
作者：
CLEMENTS, JD;NELSON, PG;REDMAN, SJ
在向猫脊髓运动神经元注射四乙铵 (TEA) 离子后，记录了单纤维 I 组兴奋性突触后电位 (e.p.s.p.s)。 TEA 注射增加了大多数 e.p.s.p.s. 的峰值幅度。 e.p.s.p.s. 的时间进程体细胞产生的能量不受影响，但 e.p.s.p.s. 的时间进程。树突中产生的时间延长。注射 TEA 后膜时间常数没有变化。体细胞 e.p.s.p.s.注入 TEA 后进行电压钳位。这些 e.p.s.p.s. 的逆转潜力。比 e.p.s.p.s. 更积极。不受茶影响。复合 e.p.s.p.s.线性地或大于线性地添加，而在没有 TEA 的运动神经元中，它们线性地或小于线性地添加。在树枝状 e.p.s.p.s. 中观察到增强的幅度和延长的时间过程。 TEA注射后通过小超极化电流减少。大于复合 e.p.s.p.s 的线性总和。通过小超极化电流转换为线性求和。体细胞 e.p.s.p.s. 的增加归因于 e.p.s.p.s 具有更积极的逆转潜力。我们认为 TEA 降低了突触下通道中 K+ 的相对渗透性。我们认为，在 TEA 存在的情况下，树突去极化会激活内向电流，从而放大并延长向体体传播的突触电位。
Single fibre group I a excitatory post-synaptic potentials (e.p.s.p.s) were recorded in cat spinal motoneurons after the neurones were injected with tetraethylammonium (TEA) ions. TEA injection increased the peak amplitude of most e.p.s.p.s. The time course of e.p.s.p.s. generated at the soma was unaffected, but the time course of e.p.s.p.s. generated in the dendrites was prolonged. The membrane time constant did not change after TEA injection. Somatic e.p.s.p.s. were voltage clamped after TEA was injected. The reversal potential for these e.p.s.p.s. was more positive than for e.p.s.p.s. unaffected by TEA. Composite e.p.s.p.s. added linearly, or greater than linearly, whereas in motoneurones without TEA they added linearly or less than linearly. The enhanced amplitude and prolonged time course observed in dendritic e.p.s.p.s. after TEA injection was reduced by small hyperpolarizing currents. Greater than linear summation of composite e.p.s.p.s. was converted to linear summation by small hyperpolarizing currents. The increase in somatic e.p.s.p.s. was attributed to a more positive reversal potential for the e.p.s.p.s. We suggest that TEA decreases the relative permeability of K+ in the subsynaptic channels. We propose that in the presence of TEA, dendritic depolarization activates an inward current which amplifies and prolongs synaptic potentials spreading towards the soma.