VILLEGAS R, VILLEGAS L, GIMENEZ M, VILLEGAS G M
J Gen Physiol. 1963 May;46(5):1047-64. doi: 10.1085/jgp.46.5.1047.
In fifty-seven resting nerve fibers of the squid Sepioteuthis sepioidea impaled from outside to inside, three potential difference (PD) levels were recorded. In twelve nerve fibers the position of the tip of the micropipette, when it was recording one of the PD levels, was labeled with carmine, and the minute spot of dye was localized histologically. The first PD level of -10 to -26 mv, was located in the endoneurium cells; the second level, formed by a single PD of -33 to -46 mv, was located in the Schwann cell; and the third level, formed by a single PD of -50 to -65 mv, was located in the axon. In sixteen nerve fibers the independence among these PD levels was demonstrated as follows. One micropipette was inserted inside the axon for recording its PD; a second one was inserted inside one endoneurium cell or inside one Schwann cell for recording the PD; and a third micropipette was inserted inside the axon to supply current to depolarize the axon. When the axon was depolarized no significant change was observed in the PD of either the endoneurium cell or the Schwann cell. In all nerve fibers action potentials were registered from the axon only. This identifies the axolemma (axon plasma membrane) as the excitable membrane.
在从外向内刺入的57条乌贼Sepioteuthis sepioidea的静息神经纤维中，记录到了三个电位差（PD）水平。在12条神经纤维中，当微吸管记录其中一个PD水平时，其尖端位置用洋红色标记，然后通过组织学方法定位微小的染料斑点。第一个PD水平为-10至-26毫伏，位于神经内膜细胞中；第二个水平由单个-33至-46毫伏的PD形成，位于施万细胞中；第三个水平由单个-50至-65毫伏的PD形成，位于轴突中。在16条神经纤维中，这些PD水平之间的独立性通过以下方式得到证明。将一个微吸管插入轴突内以记录其PD；将第二个微吸管插入一个神经内膜细胞内或一个施万细胞内以记录PD；将第三个微吸管插入轴突内以提供电流使轴突去极化。当轴突去极化时，神经内膜细胞或施万细胞的PD均未观察到明显变化。在所有神经纤维中，仅从轴突记录到动作电位。这确定轴膜（轴突质膜）为可兴奋膜。
