Vesicular glutamate transporter 2 (VGLUT2) is co-stored with PACAP in projections from the rat melanopsin-containing retinal ganglion cells
Vesicular glutamate transporter 2 (VGLUT2) is co-stored with PACAP in projections from the rat melanopsin-containing retinal ganglion cells
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DOI：
10.1007/s00441-010-0950-3
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发表时间：
2010-05-01
影响因子：
3.6
通讯作者：
Hannibal, Jens
中科院分区：
文献类型：
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作者：
Engelund, Anna;Fahrenkrug, Jan;Hannibal, Jens
眼睛的视网膜神经节细胞层包括一种以其内在光敏性和黑视素（ipRGCs）表达为特征的细胞亚型。这些细胞调节多种非图像形成（NIF）功能，如昼夜节律的光携带、运动活动的急性抑制（掩蔽）和瞳孔光反射。在ipRGCs中发现了两种神经递质，谷氨酸和垂体腺苷酸环化酶激活多肽（PACAP）。迄今为止，人们对它们的释放和相互作用知之甚少。在这里，我们描述了泡状谷氨酸转运蛋白2 （VGLUT2；谷氨酸信号的标记物）和PACAP在ipRGCs中的存在和共定位及其在大脑中的投射。9只成年雄性Wistar大鼠分为三组；顺行示踪（n = 3）、眼球摘除（n = 3）和未治疗（n = 3）。麻醉下经心灌流固定大鼠，取脑和眼，用抗vglut2多克隆抗体和小鼠单克隆抗pacap抗体进行双免疫组化染色。结果显示，VGLUT2-和pacap -免疫反应性（-ir）存在于ipRGCs中，并共同定位于它们在视交叉上核、束间小叶和橄榄叶前核的投射。我们得出的结论是，有证据支持谷氨酸和PACAP作为神经递质在大鼠ipRGCs NIF光觉中的作用，并且这些神经递质是共同储存的，可能从相同的神经末梢释放。此外，我们得出结论，VGLUT2是这些细胞使用的水泡转运蛋白的首选亚型。
The retinal ganglion cell layer of the eye comprises a subtype of cells characterized by their intrinsic photosensitivity and expression of melanopsin (ipRGCs). These cells regulate a variety of non-image-forming (NIF) functions such as light entrainment of circadian rhythms, acute suppression of locomotor activity (masking), and pupillary light reflex. Two neurotransmitters have been identified in ipRGCs, glutamate and pituitary adenylate cyclase-activating polypeptide (PACAP). To date, little is known about their release and interplay. Here, we describe the presence and co-localization of vesicular glutamate transporter 2 (VGLUT2; a marker of glutamate signaling) and PACAP in ipRGCs and their projections in the brain. Nine adult male Wistar rats were assigned to one of three groups; anterograde tracing (n = 3), eye enucleation (n = 3), and untreated (n = 3). Under anaesthesia, rats were transcardially perfusion-fixated, after which the brains and eyes were removed for double immunohistochemical staining using a polyclonal anti-VGLUT2 antibody and a mouse monoclonal anti-PACAP antibody. Results revealed that VGLUT2- and PACAP-immunoreactivity (-ir) were present in ipRGCs and co-localized in their projections in the suprachiasmatic nucleus, the intergeniculate leaflet, and the olivary pretectal nucleus. We conclude that there is evidence to support the use of glutamate and PACAP as neurotransmitters in NIF photoperception by rat ipRGCs, and that these neurotransmitters are co-stored and probably released from the same nerve terminals. Furthermore, we conclude that VGLUT2 is the preferred subtype of vesicular transporter used by these cells.