Astrocytes are essential for lipid neuronal metabolism in long-distance uninterrupted migratory flights, when glucose is not available as the main source of energy. We previously demonstrated in Calidris pusilla that after uninterrupted 5 days transatlantic flight, astrocytes shrink and reduce its number in the hippocampal formation. Here we shifted our attention to the wintering period and tested the hypothesis that hippocampal astrocyte morphology of A interpres will change as the wintering period progresses towards the premigration window. To that end we used Arenaria interpres, which also crosses the Atlantic Ocean and reaches the mangroves of the Amazon River estuary for wintering. Birds were captured in September/October (closer to the arrival in the coast of Bragança, Para, Brazil for wintering) and in April/May (closer to the departure towards the breeding sites) and had their brains processed for selective GFAP-astrocyte immunolabeling. Three-dimensional reconstructions of the immunostained astrocytes were performed and morphological classification was done based on hierarchical cluster and discriminant analysis of multimodal morphometric features. We found two morphological phenotypes of astrocytes in the newcomers which differentially increased its morphological complexities as wintering period progresses towards the pre-migration window. Taken together, our findings demonstrate that the long-distance non-stop flight and wintering period differentially affected the two astrocytes morphotypes, suggesting distinct physiological roles for these cells. We suggest that morphological changes during the wintering period, may be part of the adaptive plasticity of the local hippocampal circuits of A. interpres in preparation for the long journey back to their breeding sites in the north hemisphere.

中文翻译：

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亚马逊河河口红树林越冬期Ruddy turnstone (Arenaria interpres)海马星形胶质细胞形态的变化

当葡萄糖不能作为主要能量来源时，星形胶质细胞对于长距离不间断迁徙飞行中的脂质神经元代谢至关重要。我们之前在 Calidris pusilla 中证明，在不间断的 5 天跨大西洋飞行后，星形胶质细胞缩小并减少其在海马形成中的数量。在这里，我们将注意力转移到越冬期，并检验了随着越冬期向预迁移窗口的进展，A interpres 的海马星形胶质细胞形态将发生变化的假设。为此，我们使用了 Arenaria interpres，它也穿过大西洋，到达亚马逊河河口的红树林过冬。9 月/10 月捕获鸟类（接近抵达布拉干萨海岸，帕拉，巴西越冬）和 4 月/5 月（更接近前往繁殖地的地点），并对其大脑进行了选择性 GFAP 星形胶质细胞免疫标记处理。对免疫染色的星形胶质细胞进行三维重建，并基于层次聚类和多模态形态特征的判别分析进行形态学分类。我们在新来者中发现了两种星形胶质细胞的形态表型，随着越冬期向迁移前窗口进行，它们的形态复杂性有差异。综上所述，我们的研究结果表明，长距离不间断飞行和越冬期对两种星形胶质细胞形态类型的影响不同，表明这些细胞具有不同的生理作用。