Klooster J, Beckers H J, Vrensen G F, van der Want J J
The Netherlands Ophthalmic Research Institute, Department of Morphology, Amsterdam.
Brain Res. 1993 Dec 31;632(1-2):260-73. doi: 10.1016/0006-8993(93)91161-k.
The peripheral and central efferent projections of the rostral part of the Edinger-Westphal nucleus in the rat were investigated at the light and electron microscopic level by means of iontophoretic injections of the anterograde tracer Phaseolus vulgaris-leucoagglutinin and retrograde tracer injections of Fast blue and Nuclear yellow into the facial nucleus and into the principal olive. Two pathways leaving the rostral part of the Edinger-Westphal nucleus were studied, a peripheral and a central descending pathway. Fluorescent experiments demonstrated that the central pathway fibers originated from distinct individual Edinger-Westphal neurons. These neurons were mainly distributed throughout the rostral part of the Edinger-Westphal nucleus and had fusiform cell bodies. The neurons rarely form collateral projections. The central descending pathway left the Edinger-Westphal nucleus medially and terminated bilaterally in the principal olive, in the subnuclei A, B and C of the inferior olive and ipsilaterally in the medial accessory olive. The central pathway also terminated contralaterally in the lateral parabrachial nucleus, the facial nucleus, the trigeminal brainstem nuclear complex, the lateral reticular nucleus and the rostroventral reticular nucleus. The projection to the facial nucleus provides evidence for the existence of a polysynaptic loop forming the central part of the corneal blink reflex. Projections from the Edinger-Westphal nucleus to the cerebellar cortex or the deep nuclei, as described in cat and primate, could not be confirmed. The peripheral pathway left the Edinger-Westphal nucleus ventrally and terminated on dendrites of ciliary ganglion cells, along smooth muscle cells of ciliary ganglion associated arterioles and in the proximity of ciliary ganglion associated venules. The central and peripheral terminals that originate in the Edinger-Westphal nucleus all had similar ultrastructural features: clear, round vesicles and electron dense mitochondria. The terminals originating from the central descending pathway were often found to be arranged in glomerular-like structures. The central and peripheral terminals made asymmetric synaptic membrane specializations (Gray type one), except terminals innervating the ciliary ganglion associated vessels, which showed no synaptic contacts.
通过向面神经核和主橄榄核离子导入顺行示踪剂菜豆白细胞凝集素以及逆行示踪剂快蓝和核黄，在光镜和电镜水平研究了大鼠动眼神经核吻部的外周和中枢传出投射。研究了离开动眼神经核吻部的两条通路，一条外周下行通路和一条中枢下行通路。荧光实验表明，中枢通路纤维起源于不同的单个动眼神经核神经元。这些神经元主要分布在动眼神经核吻部，细胞体呈梭形。这些神经元很少形成侧支投射。中枢下行通路从内侧离开动眼神经核，双侧终止于主橄榄核、下橄榄核的A、B和C亚核，同侧终止于内侧副橄榄核。中枢通路还对侧终止于外侧臂旁核、面神经核、三叉神经脑干核复合体、外侧网状核和吻腹侧网状核。对面神经核的投射为形成角膜眨眼反射中枢部分的多突触回路的存在提供了证据。在猫和灵长类动物中描述的动眼神经核向小脑皮质或深部核团的投射未得到证实。外周通路从腹侧离开动眼神经核，终止于睫状神经节细胞的树突上、与睫状神经节相关小动脉的平滑肌细胞周围以及与睫状神经节相关小静脉附近。起源于动眼神经核的中枢和外周终末都具有相似的超微结构特征：清晰的圆形小泡和电子致密的线粒体。起源于中枢下行通路的终末常常排列成肾小球样结构。中枢和外周终末形成不对称的突触膜特化（I型灰质），但支配与睫状神经节相关血管的终末未显示突触联系。
