Demer J L, Poukens V, Miller J M, Micevych P
Jules Stein Eye Institute, Department of Ophthalmology, University of California at Los Angeles 90095-7002, USA.
Invest Ophthalmol Vis Sci. 1997 Aug;38(9):1774-85.
Soft pulleys stabilize paths and determine pulling directions of the extraocular muscles (EOMs). This study was conducted to characterize innervation of smooth muscles (SMs) supporting these pulleys.
Cadaveric human and monkey orbits were step and serially sectioned for histochemical and immunohistochemical staining. Before perfusion, the superior cervical ganglia of one monkey had been injected with the anterograde tracer Phaseolus vulgaris leukoagglutinin (PHA-L). Immunoperoxidase staining to human SM alpha-actin confirmed pulley SM. Monoclonal and polyclonal antibodies were used to demonstrate PHA-L, tyrosine hydroxylase, dopamine beta-hydroxylase, phenylethanolamine-N-methyltransferase, neuronal nitric oxide synthase (NOS), and synaptophysin. The NADPH-diaphorase reaction was also used as a marker for NOS and the acetylcholinesterase (AChE) reaction for acetylcholine.
Pulleys, consisting of collagen and elastin sleeves supported by connective tissue containing SM, were observed around rectus muscles of humans and monkeys. The human and monkey SM was richly innervated. Axons terminating in motor end plates within SM bundles were immunoreactive to PHA-L, tyrosine hydroxylase, and dopamine beta-hydroxylase, but not phenylethanolamine-N-methyltransferase, indicating innervation of pulley SM from the superior cervical ganglion by projections using norepinephrine. Smaller axons and motor end plates were also demonstrated in SM, using NADPH-diaphorase and NOS immunoreactivity, indicating nitroxidergic innervation, and using AchE, indicating cholinergic parasympathetic innervation. The pterygopalatine and, to a lesser extent, the ciliary ganglia, but not the Edinger-Westphal nucleus, contained cells immunoreactive to NOS, suggesting that nitroxidergic innervation to pulley SM is mainly from the pterygopalatine ganglion.
The SM suspensions of human and monkey EOM pulleys are similar and receive rich innervation involving multiple neurotransmitters. These complex projections suggest excitatory and inhibitory control of EOM pulley SM, and support their dynamic role in ocular motility.
软性滑车稳定眼外肌的运动路径并决定其牵拉方向。本研究旨在描述支持这些滑车的平滑肌的神经支配情况。
对人类和猴子的尸体眼眶进行阶梯状连续切片，用于组织化学和免疫组织化学染色。在灌注前，向一只猴子的颈上神经节注射顺行示踪剂菜豆白细胞凝集素（PHA-L）。用免疫过氧化物酶染色检测人类平滑肌α-肌动蛋白以确认滑车平滑肌。使用单克隆和多克隆抗体来显示PHA-L、酪氨酸羟化酶、多巴胺β-羟化酶、苯乙醇胺-N-甲基转移酶、神经元型一氧化氮合酶（NOS）和突触素。NADPH-黄递酶反应也用作NOS的标志物，乙酰胆碱酯酶（AChE）反应用于检测乙酰胆碱。
在人类和猴子的直肌周围观察到由含有平滑肌的结缔组织支撑的胶原和弹性蛋白袖套组成的滑车。人类和猴子的平滑肌有丰富的神经支配。终止于平滑肌束内运动终板的轴突对PHA-L、酪氨酸羟化酶和多巴胺β-羟化酶有免疫反应，但对苯乙醇胺-N-甲基转移酶无反应，表明颈上神经节通过去甲肾上腺素投射对滑车平滑肌有神经支配。利用NADPH-黄递酶和NOS免疫反应性在平滑肌中也显示出较小的轴突和运动终板，表明有含氮氧化物能神经支配，利用AChE表明有胆碱能副交感神经支配。翼腭神经节以及程度较轻的睫状神经节含有对NOS有免疫反应的细胞，而动眼神经副核则没有，这表明对滑车平滑肌的含氮氧化物能神经支配主要来自翼腭神经节。
人类和猴子眼外肌滑车的平滑肌悬韧带相似，接受涉及多种神经递质的丰富神经支配。这些复杂的投射提示对眼外肌滑车平滑肌有兴奋和抑制性控制，并支持它们在眼球运动中的动态作用。
