Brink E, Harrison P J, Jankowska E, McCrea D A, Skoog B
J Physiol. 1983 Oct;343:341-59. doi: 10.1113/jphysiol.1983.sp014896.
The technique of recording post-synaptic potentials from a population of motoneurones, by recording from ventral roots perfused with isotonic sucrose, has been applied to investigate the action of single last-order interneurones; the target motoneurones were in either caudal L7 or S1 segments. Using spike-triggered averaging, the inhibitory action of 70% of previously identified last-order interneurones (Renshaw cells and lamina VII Ia inhibitory interneurones) has been detected. Previous observations had suggested that interneurones mediating disynaptic non-reciprocal inhibition from group I muscle afferents should be characterized by (i) location in laminae V-VI, (ii) monosynaptic group I input and (iii) ascending collateral axonal projection to upper lumbar segments. 65% of interneurones with these characteristics were found to inhibit motoneurones. In addition, spike-triggered averaging from this group of laminae V-VI interneurones sometimes revealed a depolarizing potential which preceded the inhibitory potential evoked by the interneurone. The depolarizing potential is interpreted as being due to the action of some presynaptic fibres which branch to innervate both the investigated interneurones and motoneurones.
通过记录用等渗蔗糖灌注的腹根来记录一群运动神经元的突触后电位的技术，已被用于研究单个最后一级中间神经元的作用；目标运动神经元位于尾侧L7或S1节段。使用触发尖峰平均法，已检测到70%先前鉴定的最后一级中间神经元（伦肖细胞和VII层Ia抑制性中间神经元）的抑制作用。先前的观察表明，介导来自I组肌肉传入纤维的双突触非相互抑制的中间神经元应具有以下特征：（i）位于V-VI层，（ii）单突触I组输入，以及（iii）向腰上段的上行侧支轴突投射。发现具有这些特征的中间神经元中有65%抑制运动神经元。此外，从这群V-VI层中间神经元进行的触发尖峰平均有时会显示出一个去极化电位，该电位先于中间神经元诱发的抑制电位出现。去极化电位被解释为是由于一些突触前纤维的作用，这些纤维分支以支配被研究的中间神经元和运动神经元。
