蜗牛巨型神经元中体细胞动作电位与轴突动作电位之间的离子差异。

The ionic requirements of the somatic and axonal action potentials of ;H' neurones of the snail Cryptomphallus aspersa were studied using intracellular micro-electrodes.2. The overshoot of the somatic action potential increased by 10 mV for a tenfold increase in Ca(2+). In calcium-free media the action potential decreased gradually to values of 50 to 90% of the control and they could be completely eliminated with 2 mM-EGTA. The maximum rate of rise also varied with Ca(2+).3. After 2 hr in sodium-free solution the somatic action potential decreased 6% in overshoot and 24% in rate of rise.4. The somatic action potential was not affected by TTX, 5 x 10(-6) g/ml. Procaine, 18 mM, reduced its rate of rise but did not eliminate it whereas 30 mM-CoCl(2) did.5. The size of the axonal action potential increased with increased Na(+), but decreased with an increase in Ca(2+).6. Procaine, 18 mM, abolished the axonal action potential whereas it was not affected by TTX, 5 x 10(-6) g/ml., nor, usually, by 30 mM-CoCl(2).7. The results obtained by studying the compound action potential of the nerves were similar to those from axonal action potentials.8. The possibility that the somatic action potential is mainly calcium dependent while the axonal action potential is mainly produced by sodium is discussed.

利用细胞内微电极研究了蜗牛隐孔螺H'神经元的体细胞动作电位和轴突动作电位的离子需求。
体细胞动作电位的超射值随[Ca(2+)]（o）增加十倍而增加10 mV。在无钙培养基中，动作电位逐渐下降至对照值的50%至90%，用2 mM - EGTA可将其完全消除。最大上升速率也随[Ca(2+)]（o）变化。
在无钠溶液中放置2小时后，体细胞动作电位的超射值下降6%，上升速率下降24%。
体细胞动作电位不受5×10(-6) g/ml的TTX影响。18 mM的普鲁卡因降低了其上升速率，但未消除，而30 mM的CoCl(2)则消除了它。
轴突动作电位的大小随[Na(+)]（o）增加而增加，但随[Ca(2+)]（o）增加而减小。
18 mM的普鲁卡因消除了轴突动作电位，而它不受5×10(-6) g/ml的TTX影响，通常也不受30 mM的CoCl(2)影响。
通过研究神经复合动作电位获得的结果与轴突动作电位的结果相似。
讨论了体细胞动作电位主要依赖钙而轴突动作电位主要由钠产生的可能性。

Ionic differences between somatic and axonal action potentials in snail giant neurones.