Villegas J
J Physiol. 1973 Jul;232(1):193-208. doi: 10.1113/jphysiol.1973.sp010264.
The effects of eserine and D-tubocurarine on the axon and Schwann cell membrane potentials have been studied in the giant nerve fibre of the squid.1. The addition of eserine at concentrations of up to 10(-4)M to the external sea-water medium has no appreciable effects on either the Schwann cell electrical potential of unstimulated nerve fibres or on the resting and action potentials of the axon.2. However, eserine at a concentration of 10(-9)M prolongs the long-lasting Schwann cell hyperpolarizations which follow the conduction of impulse trains by the axon.3. Higher concentrations of eserine (10(-7), 10(-4)M) decrease and block the long-lasting effects of nerve impulse train conduction.4. D-tubocurarine at concentrations of up to 10(-5)M has no appreciable effect on the resting and action potentials of the axon.5. However, D-tubocurarine at a concentration of 10(-9)M blocks completely the hyperpolarizing effects of nerve impulse trains on the Schwann cell electrical potential.6. In addition to its blocking action, D-tubocurarine induces transient hyperpolarizations in the Schwann cells of unstimulated nerve fibres both in intact fibres and in slitted preparations.7. These findings suggest that a cholinergic system, which may be located at the axon-Schwann cell boundary, is involved in the genesis of the long-lasting Schwann cell hyperpolarization caused by the conduction of nerve impulse trains by the axon.
已在鱿鱼的巨大神经纤维中研究了毒扁豆碱和筒箭毒碱对轴突和施万细胞膜电位的影响。
向外部海水介质中添加浓度高达10⁻⁴M的毒扁豆碱，对未受刺激神经纤维的施万细胞电位或轴突的静息电位和动作电位均无明显影响。
然而，浓度为10⁻⁹M的毒扁豆碱可延长轴突传导冲动序列后施万细胞持续的超极化。
更高浓度的毒扁豆碱（10⁻⁷、10⁻⁴M）会降低并阻断神经冲动序列传导的长期效应。
浓度高达10⁻⁵M的筒箭毒碱对轴突的静息电位和动作电位无明显影响。
然而，浓度为10⁻⁹M的筒箭毒碱完全阻断了神经冲动序列对施万细胞电位的超极化作用。
除了其阻断作用外，筒箭毒碱在完整纤维和切开的标本中均可诱导未受刺激神经纤维的施万细胞出现短暂的超极化。
这些发现表明，一个可能位于轴突 - 施万细胞边界的胆碱能系统参与了轴突传导神经冲动序列所引起的施万细胞持续超极化的发生过程。
