Molotchnikoff S, Casanova C
J Neurosci Res. 1985;14(1):105-15. doi: 10.1002/jnr.490140110.
The aim of these investigations was to advance our knowledge of the influence of extrinsic ocular muscle (EOM) stretching on cell excitability of the retinocortical pathway. The initial goal was the lateral geniculate; however, histologic analysis indicated that most cells that responded to stretching were located near its superior edge, in an area analogous to the perigeniculate. Rabbits were anaesthetized and prepared for single-cell recordings. The extraocular muscles were detached from the eye and attached to a rigid tungsten hook. The hook was soldered to the pivot of a galvanometer that was controlled by a waveform generator. Precise and repeated length changes were obtained with extension and relaxation ramps of constant velocity. Thirty percent of the units (N = 250) responded to EOM stretching. These stimuli evoked either an excitation or a decrease of the units' spontaneous activity. Several experimental controls provided evidence that the signals that evoked the geniculate responses originated from proprioceptors belonging to the EOM. Most responding cells had their receptive fields located eccentrically (greater than or equal to 50 degrees). Also, cells that reacted to EOM stretching responded to optic nerve stimulation with a significantly shorter latency than cells that were unresponsive. Pairing the EOM stretching with light stimuli produced the following results. In about half of the units the light-evoked responses augmented, but in 28% of the cells the light-evoked discharges decreased. These effects were obtained even though EOM stretching delivered singly failed to elicit a reaction from the cell. Histologic reconstructions indicated that cells were distributed in a discrete region lying rostral and dorsomedial to the lateral geniculate nucleus. This area has been associated with the perigeniculate nucleus in cats and rats.
这些研究的目的是增进我们对眼外肌（EOM）拉伸对视皮层通路细胞兴奋性影响的了解。最初的目标是外侧膝状体；然而，组织学分析表明，大多数对拉伸有反应的细胞位于其 superior edge 附近，在一个类似于膝状体周的区域。兔子被麻醉并准备进行单细胞记录。眼外肌从眼睛分离并连接到一个刚性钨钩上。该钩焊接到由波形发生器控制的检流计的枢轴上。通过等速的伸展和松弛斜坡获得精确且重复的长度变化。30% 的单位（N = 250）对 EOM 拉伸有反应。这些刺激引起单位自发活动的兴奋或降低。几个实验对照提供了证据，表明引起膝状体反应的信号源自属于 EOM 的本体感受器。大多数有反应的细胞的感受野位于偏心位置（大于或等于 50 度）。此外，对 EOM 拉伸有反应的细胞对视神经刺激的反应潜伏期明显短于无反应的细胞。将 EOM 拉伸与光刺激配对产生了以下结果。在大约一半的单位中，光诱发反应增强，但在 28% 的细胞中，光诱发放电减少。即使单独进行 EOM 拉伸未能引起细胞反应，也能获得这些效果。组织学重建表明，细胞分布在外侧膝状体核的 rostral 和 dorsomedial 的离散区域。这个区域在猫和大鼠中与膝状体周核有关。
