Billig I, Buisseret Delmas C, Buisseret P
Anatomie Comparée, Muséum National d'Histoire Naturelle, and CNRS/Collège de France, Paris.
Anat Rec. 1997 Aug;248(4):566-75. doi: 10.1002/(SICI)1097-0185(199708)248:4<566::AID-AR8>3.0.CO;2-J.
The aim of the present study was to identify the varieties of sensory and motor nerve endings in cat extraocular muscles.
Sensory terminals were identify by injecting neuronal tracers (fast blue, biocytin, or peroxidase) into the trigeminal ganglion, which contains the sensory cells innervating the eye muscles. Motor terminals were identified by injections of horseradish peroxidase or DiI, a fluorescent carbocyanin dye, into either the oculomotor nerve or the IIIrd nuclei.
Injections into the trigeminal ganglion anterogradely labelled three types of sensory nerve endings for each neuronal tracer used: (1) the well-known "palisade" endings at the myotendinous junction of each extraocular muscle; (2) "compact" endings consisting of a dense terminal arborization extending up to 60 microm in length on striated muscle fibres 10-15 microm in diameter; and (3) "complex" endings on muscle fibres 15-20 microm in diameter. The complex ending issued from multiple collateral branches of the parent nerve fibre, which stretched and turned around the muscle fibre and gave off numerous terminal varicosities over a distance of about 140 microm. The sensory complex and compact endings presented strong similarities with some "atypical muscle spindles" previously described. In addition to the classic motor "plate" and "grape," we found evidence for the existence of motor "spiral" endings with each tracer.
The sensory nature of the palisade endings was demonstrated, and two other types of sensory terminals were identified and described. The spiral nerve terminals were demonstrated to be motor in nature, and a possible function in the microsaccadic movements associated with fixation is suggested.
本研究的目的是确定猫眼外肌中感觉神经末梢和运动神经末梢的种类。
通过将神经元示踪剂（快蓝、生物素或过氧化物酶）注入三叉神经节来识别感觉末梢，三叉神经节包含支配眼肌的感觉细胞。通过将辣根过氧化物酶或一种荧光碳氰染料DiI注入动眼神经或动眼神经核来识别运动末梢。
向三叉神经节注射后，每种使用的神经元示踪剂都顺行标记了三种类型的感觉神经末梢：（1）每条眼外肌肌腱结合处的著名的“栅栏状”末梢；（2）“致密”末梢，由密集的终末分支构成，在直径为10 - 15微米的横纹肌纤维上延伸长达60微米；（3）直径为15 - 20微米的肌纤维上的“复杂”末梢。复杂末梢由母神经纤维的多个侧支发出，这些侧支在肌纤维周围伸展并环绕，在约140微米的距离内发出许多终末膨体。感觉复杂末梢和致密末梢与先前描述的一些“非典型肌梭”有很强的相似性。除了经典的运动“板状”和“葡萄状”末梢外，我们还发现每种示踪剂都有运动“螺旋状”末梢存在的证据。
证实了栅栏状末梢的感觉性质，识别并描述了另外两种类型的感觉末梢。证实了螺旋状神经末梢本质上是运动性的，并提出了其在与注视相关的微扫视运动中的可能功能。
