Hutchins J B, Bernanke J M, Jefferson V E
Department of Anatomy, University of Mississippi Medical Center, Jackson 39216-4505, USA.
Exp Eye Res. 1995 Feb;60(2):113-25. doi: 10.1016/s0014-4835(95)80001-8.
The function of acetylcholinesterase (AChE) is to terminate the action of acetylcholine at the cholinergic synapse. Recent evidence suggests additional roles for acetylcholinesterase as a peptidase and/or a protease which is expressed by growing neurites as part of their invasion of developing neural structures. We report the localization of acetylcholinesterase in developing ferret retina. AChE histochemical staining is seen in the developing inner plexiform layer (IPL) of ferret retina at birth (post-natal day zero, PO), the earliest developmental stage examined. Transient expression is seen at the border between the ganglion cell layer and the nerve fiber layer at P14 and P21. A small amount of transient expression is seen in the outer plexiform layer (OPL) at this age as well. By P28, the transient expression in the OPL is at its peak, and is found at photoreceptor terminals and associated with apparent horizontal cell axons. Labeling is also seen intracellularly in the inner nuclear layer (INL), at the OPL/INL border, suggesting that horizontal cells are the source of the transient AChE expression in the OPL. Overt synaptic profiles also appear in the inner plexiform layer (IPL) at P21 and P28. About 2 days layer, the eyes open and the photoreceptor outer segments are fully developed. By 2 weeks later, at P42, the AChE staining pattern in the retina has taken on its adult appearance: no reaction product in the outer retina; intracellular reaction product in the Golgi apparatus of a subset of amacrine and displaced amacrine cells which manufacture AChE; and extracellular reaction product at both synaptic and non-synaptic sites in the IPL. These data are consistent with a role for AChE as a peptidase early in development, and as an enzyme essential in the termination of synaptic action at mature synapses.
乙酰胆碱酯酶（AChE）的功能是在胆碱能突触处终止乙酰胆碱的作用。最近的证据表明，乙酰胆碱酯酶作为一种肽酶和/或蛋白酶具有额外的作用，它由生长中的神经突表达，是其侵入发育中的神经结构的一部分。我们报告了乙酰胆碱酯酶在雪貂发育视网膜中的定位。在出生时（出生后第0天，P0），即所检查的最早发育阶段，在雪貂视网膜发育中的内网状层（IPL）可见AChE组织化学染色。在P14和P21时，在神经节细胞层和神经纤维层之间的边界处可见短暂表达。在这个年龄段，在外网状层（OPL）也可见少量短暂表达。到P28时，OPL中的短暂表达达到峰值，在光感受器终末可见，并且与明显的水平细胞轴突相关。在内核层（INL）内、OPL/INL边界处也可见细胞内标记，提示水平细胞是OPL中短暂AChE表达的来源。在P21和P28时，内网状层（IPL）中也出现明显的突触轮廓。大约2天后，眼睛睁开，光感受器外段完全发育。2周后，即P42时，视网膜中的AChE染色模式呈现出成年外观：外视网膜无反应产物；在制造AChE的无长突细胞和移位无长突细胞亚群的高尔基体中有细胞内反应产物；在IPL的突触和非突触部位均有细胞外反应产物。这些数据与AChE在发育早期作为肽酶的作用以及在成熟突触处终止突触作用中作为必需酶的作用一致。
