Ionic mechanisms mediating 5‐hydroxytryptamine‐ and noradrenaline‐evoked depolarization of adult rat facial motoneurones.
Ionic mechanisms mediating 5‐hydroxytryptamine‐ and noradrenaline‐evoked depolarization of adult rat facial motoneurones.
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介导 5-羟色胺和去甲肾上腺素诱发成年大鼠面部运动神经元去极化的离子机制。
DOI：
10.1113/jphysiol.1992.sp019347
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
J. S. Kelly
中科院分区：
文献类型：
--
作者：
P. M. Larkman;J. S. Kelly
1.应用细胞内记录技术研究了5-羟色胺（5-HT）和去甲肾上腺素（NA）对离体成年大鼠脑干脑片面运动神经元膜特性的影响。2.在电压钳记录中，超极化电压阶跃（> 20 mV），从保持电位处于或接近静息电位，诱导一个缓慢激活的电压依赖性内向电流，其性质与其他细胞类型中观察到的超极化激活电流（Ih）相似。根据尾电流分析，可以根据Ih的激活范围区分两组面部运动神经元，一组在-81 mV处具有半最大激活，另一组在-94 mV处具有相似的形状。3. 5-HT（120/126）和NA（21/21）去极化面运动神经元。在不同的细胞外钾浓度下，从峰值电压幅度I-V图获得的逆转电位（Em）表明了涉及K+电导降低的机制。4.在电压钳下，接近静息电位时，5-HT（39/41）和NA（13/13）均诱发内向电流。5.不同膜电位下的I-V曲线和5-HT敏感电流曲线，由电压阶跃诱发的电流获得，并在Ih发展前测量（瞬时电流），表明5-HT诱发的内向电流主要与电导降低相关，但5-HT（E5-HT）的逆转电位范围从接近，到比钾电导（EK）的反转电位负得多。在某些情况下，没有观察到瞬时电导的变化或增加。6.稳态I-V关系和5-HT敏感电流图（在Ih形成后测量）表明，5-HT相关电导随时间和电压依赖性增加，接近Ih，可被细胞外铯（2 - 5 mM）消除。7. NA诱发的内向电流总是与电导降低相关。瞬时和稳态I-V关系以及NA敏感电流图表明在EK处存在反转电位。8.在存在5-HT的情况下，Ih的激活曲线向更正的电位移动。Ih激活的时间常数显示出类似的变化。9. 5-羟色胺受体激动剂5-羧酰胺色胺（5-CT）对Ih的增强具有选择性，只有当保持电位在Ih的激活范围内时才能诱发内向电流。（400字处截断摘要）
1. The actions of 5‐hydroxytryptamine (5‐HT) and noradrenaline (NA) on the membrane properties of facial motoneurones in slices from the adult rat brainstem in vitro were examined using intracellular recording techniques. 2. In voltage clamp recording, hyperpolarizing voltage steps (> 20 mV), from holding potentials at or close to the resting potential, induced a slowly activating, voltage‐dependent inward current possessing properties similar to the hyperpolarization‐activated current (Ih) seen in other cell types. From tail current analysis two groups of facial motoneurones can be distinguished in terms of the activation range for Ih, one with a half‐maximal activation at ‐81 mV and the other at ‐94 mV but with similar shapes. 3. 5‐HT (120/126) and NA (21/21) depolarized facial motoneurones. The reversal potentials (Em) obtained from peak voltage amplitude I‐V plots in varying extracellular potassium concentrations suggested mechanisms involving a decrease in K+ conductance. 4. Under voltage clamp, close to the resting potential, both 5‐HT (39/41) and NA (13/13) evoked inward currents. 5. I‐V plots and plots of 5‐HT‐sensitive current at different membrane potentials, obtained from currents evoked by voltage steps and measured before the development of Ih (instantaneous current), indicated that the 5‐HT‐evoked inward current was predominately associated with a decrease in conductance but with a range of reversal potentials for 5‐HT (E5‐HT) from close to, to much more negative than the reversal potential for a potassium conductance (EK). In some cases no change or increases in instantaneous conductance were observed. 6. Steady‐state I‐V relationships and plots of 5‐HT‐sensitive current, measured after development of Ih, indicated a 5‐HT‐associated conductance increase with a time and voltage dependence close to that of Ih, which could be abolished by extracellular caesium (2‐5 mM). 7. The NA‐evoked inward current was always associated with a decrease in conductance. Instantaneous and steady‐state I‐V relationships as well as plots of NA‐sensitive current indicated a reversal potential at EK. 8. The activation curve for Ih was shifted to more positive potentials in the presence of 5‐HT. The time constant for activation of Ih showed a similar shift. 9. 5‐Carboxamidotryptamine (5‐CT), a 5‐HT receptor agonist, was selective for the enhancement of Ih and only evoked an inward current when the holding potential was within the activation range of Ih.(ABSTRACT TRUNCATED AT 400 WORDS)
大鼠伏隔核神经元的内向整流。
影响因子：
2.5
作者：
Uchimura,N;Cherubini,E;North,RA
通讯作者：
North,RA
异常整流器激活对体外猫感觉运动皮层神经元后超极化的影响。
影响因子：
2.5
作者：
Schwindt,PC;Spain,WJ;Crill,WE
通讯作者：
Crill,WE
P物质对培养大鼠脑胆碱能神经元内向整流通道的调节。
DOI：
10.1113/jphysiol.1990.sp018151
发表时间：
1990
期刊：
The Journal of physiology
影响因子：
--
作者：
Yamaguchi,K;Nakajima,Y;Nakajima,S;Stanfield,PR
通讯作者：
Stanfield,PR