青蛙肌梭在受到拉伸后放电的适应性。

Adaptation of the discharge of frog muscle spindles following a stretch.

Brokensha G, Westbury D R

J Physiol. 1974 Oct;242(2):383-403. doi: 10.1113/jphysiol.1974.sp010713.

Abstract

Stretching a frog muscle spindle evoked a discharge of action potentials in its sensory axon. As the rate of this discharge decreased during the adaptation that followed the dynamic phase of a stretch, the variability of the interspike intervals of the impulse train increased.2. Adaptation occurred in two phases. At first the impulse train was almost regular and adapted rapidly, but later this gave way to a phase of slower adaptation where the variability of the discharge was much increased. In the second phase of adaptation the interspike intervals increased in length less than half as quickly as in the first phase.3. When the rate of adaptation changed from the more rapid to the slower phase there was often an abrupt change in the character of the discharge and the relationship between the mean interspike interval and the variability changed. The interspike interval at which this change-over occurred was relatively constant in records of the discharge from one afferent fibre even though stretches of different amplitude were employed, though it differed from one afferent fibre to another.4. These features of the discharge during adaptation suggest that the two sections of the impulse trains were derived from different spike generators by a process of probabilistic mixing.

摘要

拉伸青蛙的肌梭会在其感觉轴突中诱发动作电位发放。在拉伸动态阶段之后的适应过程中，随着这种发放速率的降低，冲动序列的峰峰间隔变异性增加。
适应过程分两个阶段发生。起初，冲动序列几乎是规则的且快速适应，但后来这让位于适应较慢的阶段，此时发放的变异性大幅增加。在适应的第二阶段，峰峰间隔长度增加的速度不到第一阶段的一半。
当适应速率从较快阶段转变为较慢阶段时，发放特征通常会突然改变，平均峰峰间隔与变异性之间的关系也会改变。即使采用了不同幅度的拉伸，从一根传入纤维的放电记录来看，发生这种转变的峰峰间隔相对恒定，不过不同传入纤维之间存在差异。
适应过程中发放的这些特征表明，冲动序列的这两个部分是通过概率混合过程由不同的峰电位发生器产生的。