The purpose of the present study was to investigate the organization of choline acetyltransferase (ChAT)-immunoreactive (IR) fibers in the visual cortex of the microbat, using standard immunocytochemistry and confocal microscopy. ChAT-IR fibers were distributed throughout all layers of the visual cortex, with the highest density in layer III and the lowest density in layer I. However, no ChAT-IR cells were found in the microbat visual cortex. ChAT-IR fibers were classified into two types: small and large varicose fibers. Previously identified sources of cholinergic fibers in the mammalian visual cortex, the nucleus of the diagonal band, the substantia innominata, and the nucleus basalis magnocellularis, all contained strongly labeled ChAT-IR cells in the microbat. The average diameter of ChAT-IR cells in the nucleus of the diagonal band, the substantia innominata, and the nucleus basalis magnocellularis was 16.12 μm, 13.37 μm, and 13.90 μm, respectively. Our double-labeling study with ChAT and gamma-aminobutyric acid (GABA), and triple labeling with ChAT, GABA, and post synaptic density 95 (PSD-95), suggest that some ChAT-IR fibers make contact with GABAergic cells in the microbat visual cortex. Our results should provide a better understanding of the nocturnal bat visual system.

中文翻译：

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胆碱乙酰转移酶在Microbat视觉皮层中的免疫细胞化学定位。

本研究的目的是使用标准免疫细胞化学和共聚焦显微镜研究微蝙蝠视皮层中胆碱乙酰基转移酶（ChAT）-免疫反应性（IR）纤维的组织。ChAT-IR纤维分布在视觉皮层的所有层中，其中III层的密度最高，而I层的密度最低。但是，在Microbat视觉皮层中未发现ChAT-IR细胞。ChAT-IR纤维分为两种类型：小型和大型静脉曲张纤维。以前确定的哺乳动物视觉皮层，对角带的核，无名状的物质和基底细胞的基底核中的胆碱能纤维的来源，都在微球中包含强标记的ChAT-IR细胞。ChAT-IR细胞在对角带核中的平均直径，无名状实体和基底细胞核分别为16.12μm，13.37μm和13.90μm。我们使用ChAT和γ-氨基丁酸（GABA）进行的双标记研究以及使用ChAT，GABA和突触后密度95（PSD-95）进行的三重标记研究表明，某些ChAT-IR纤维会与微蝙蝠中的GABA能细胞接触视觉皮层。我们的结果应提供对夜间蝙蝠视觉系统的更好理解。