乙酰胆碱对海兔胸膜神经节腹尾感觉神经元的作用。

Effect of acetylcholine on ventrocaudal sensory neurons in the pleural ganglia of Aplysia.

Ichinose M, Sawada M, Maeno T, McAdoo D J

Department of Physiology, Shimane Medical University, Izumo, Japan.

Cell Mol Neurobiol. 1989 Jun;9(2):233-45. doi: 10.1007/BF00713031.

Abstract

The effects of acetylcholine (ACh) on the soma of cultured ventrocaudal sensory neurons from the pleural ganglia of Aplysia kurodai were characterized. 2. Whole-cell recording was used for current and voltage clamping. ACh and other drugs were microapplied to the membranes of the cultured neurons. 3. Microapplication of ACh induced an outward current mediated by a conductance increase. No desensitization to repeated applications of ACh was detected. The threshold was 10(-7) M and the maximum response was at 10(-5) M. 4. The reversal potential in normal seawater is -80 mV, close to the K+ equilibrium potential. Increasing [K+]0 shifted the reversal potential by the amount predicted by the Nernst equation. Altering [Cl-]0 did not affect the reversal potential. Thus ACh opens a potassium channel in these sensory neurons and may act as a neurotransmitter on those neurons. 5. Atropine and d-tubocurarine partially blocked the ACh response. Hexamethonium had no obvious effect on this response. Tetraethylammonium reduced the response to 22% of control. Carbamylcholine and arecoline induced outward currents that were 71 and 12%, respectively, of the response to ACh. Nicotine and muscarine had almost no effect. 6. The ACh response was reduced by prior application of serotonin (5HT). The ACh response was also reduced by bath-applied 5HT, forskolin, and isobutylmethylxanthine. These data suggest that ACh activates an "S-like" channel in the ventrocaudal sensory neurons.

摘要

研究了乙酰胆碱（ACh）对黑尾海兔胸膜神经节培养的腹侧尾侧感觉神经元胞体的作用。2. 采用全细胞记录进行电流钳制和电压钳制。将ACh和其他药物微量施加到培养神经元的膜上。3. 微量施加ACh可诱导由电导增加介导的外向电流。未检测到对重复施加ACh的脱敏现象。阈值为10^(-7) M，最大反应出现在10^(-5) M。4. 在正常海水中反转电位为 -80 mV，接近K+平衡电位。增加[K+]0使反转电位按能斯特方程预测的量发生偏移。改变[Cl-]0不影响反转电位。因此，ACh在这些感觉神经元中打开了一个钾通道，并且可能在这些神经元上作为神经递质起作用。5. 阿托品和d - 筒箭毒碱部分阻断了ACh反应。六甲铵对该反应无明显影响。四乙铵将反应降低至对照的22%。氨甲酰胆碱和槟榔碱分别诱导出为ACh反应71%和12%的外向电流。尼古丁和毒蕈碱几乎没有影响。6. 预先施加5 - 羟色胺（5HT）可降低ACh反应。浴加5HT、福斯可林和异丁基甲基黄嘌呤也可降低ACh反应。这些数据表明，ACh在腹侧尾侧感觉神经元中激活了一个“类S”通道。