Histamine immunoreactive axons in the macaque retina.
Histamine immunoreactive axons in the macaque retina.
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DOI：
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发表时间：
1999-02
影响因子：
4.4
通讯作者：
M. J. Gastinger;J. O’Brien;N. B. Larsen;D. Marshak
中科院分区：
文献类型：
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作者：
M. J. Gastinger;J. O’Brien;N. B. Larsen;D. Marshak
目的研究猕猴视网膜离心性轴突中的神经递质。方法用碳化二亚胺固定猕猴视网膜和视神经过夜，用免疫荧光技术标记组胺抗血清。结果几个大的组胺免疫反应轴突从视神经头到周围视网膜，在那里它们广泛地分支并终止于内丛状层，有时沿着视网膜血管。从视神经头出来的其他轴突穿过光纤层到达中央视网膜，绕过中心凹，然后回到视盘。这些可能是在中央视觉区域观察到的组胺免疫反应轴突的来源。视网膜内未见标记细胞体。由于下丘脑后部的核周是灵长类中枢神经系统中唯一已知的组胺来源，而且那里的神经元可以从切断的视神经逆行标记，组胺免疫反应轴突肯定起源于那里。结论猕猴视网膜中的离心性轴突是含有组胺的轴突系统的一部分，组胺起源于下丘脑，投射到整个大脑。由于这些神经元的活动在早上最高，组胺可能在为视网膜在白天运行做好准备方面发挥作用。组胺免疫反应轴突与血管的接触表明，组胺也可能在调节视网膜微血管系统中发挥作用。
PURPOSE The goal of these experiments was to identify the neurotransmitter in centrifugal axons of the macaque retina. METHODS Macaca mulatta retinas and optic nerves were fixed overnight in carbodiimide and labeled with an antiserum to histamine with the use of an immunofluorescence technique. RESULTS Several large histamine-immunoreactive axons ran from the optic nerve head to the peripheral retina, where they branched extensively and terminated in the inner plexiform layer, occasionally alongside retinal blood vessels. Other axons that emerged from the optic nerve head ran in the optic fiber layer to the central retina, circled the fovea, and then returned to the optic disc. These may be the source of histamine-immunoreactive axons that have been observed in central visual areas. No labeled cell bodies were present in the retina. Because perikarya in the posterior hypothalamus are the only known source of histamine in the primate central nervous system and because neurons there can be retrogradely labeled from the cut optic nerve, the histamine-immunoreactive axons must have originated there. CONCLUSIONS Centrifugal axons in the macaque retina are part of the system of axons containing histamine that originate in the hypothalamus and project throughout the brain. Because the activity of these neurons is highest during the morning, histamine might play a role in preparing the retina to operate in daylight. The contacts of histamine-immunoreactive axons with blood vessels suggest that histamine may also play a role in regulating the retinal microvasculature.