Labandeira-Garcia J L, Guerra-Seijas M J, Segade L A, Suarez-Nuñez J M
J Comp Neurol. 1987 May 1;259(1):140-9. doi: 10.1002/cne.902590110.
The location of the motoneurons innervating the lateral rectus, pyramidalis, and quadratus muscles of the chick has been determined by application of horseradish peroxidase (HRP) to these muscles and their nerve branches, and internuclear neurons in the abducens nucleus have been identified by injection of HRP into the oculomotor nucleus. Quantitative results were obtained by means of a semiautomatic image analyzer. Lateral rectus motoneurons were observed only in the ipsilateral principal abducens nucleus, where they numbered 500-550, and quadratus and pyramidalis motoneurons only in the ipsilateral accessory abducens nucleus. The 325-375 internuclear neurons that appeared in the principal abducens nucleus contralateral to the oculomotor nucleus injected with HRP were practically confined to the rostral two thirds of the nucleus, where they tended to surround the lateral rectus motoneurons in dorsal or lateral positions, though a minority of interneurons also mingled with the motoneurons in the center or at the medial face of the nucleus. Most interneurons were small and elongated, but a minority of larger interneurons morphologically similar to the lateral rectus motoneurons were also distinguishable. The 100-110 quadratus motoneurons and the 45-55 pyramidalis motoneurons mingled in the accessory abducens nucleus were larger than the lateral rectus motoneurons and sent their axons into the ipsilateral abducens nerve.
通过将辣根过氧化物酶（HRP）应用于鸡的外直肌、锥状肌和方肌及其神经分支，确定了支配这些肌肉的运动神经元的位置，并通过将HRP注入动眼神经核来识别展神经核中的核间神经元。借助半自动图像分析仪获得了定量结果。仅在同侧展神经主核中观察到外直肌运动神经元，其数量为500 - 550个，而方肌和锥状肌运动神经元仅在同侧展神经副核中观察到。在向其注射HRP的动眼神经核的对侧展神经主核中出现的325 - 375个核间神经元实际上局限于该核的前三分之二，它们倾向于在背侧或外侧围绕外直肌运动神经元，尽管少数中间神经元也在核的中央或内侧与运动神经元混合。大多数中间神经元小且呈细长形，但也可区分出少数形态上与外直肌运动神经元相似的较大中间神经元。在展神经副核中混合的100 - 110个方肌运动神经元和45 - 55个锥状肌运动神经元比外直肌运动神经元大，并将其轴突发送到同侧展神经中。
