Laboratório de Biologia Molecular e Neuroecologia, Instituto Federal de Educação Ciência e Tecnologia do Pará, Campus Bragança, Bragança, Pará, Brazil.
Laboratório de Investigações em Neurodegeneração e Infecção no Hospital Universitário João de Barros Barreto, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém, Pará, Brazil.
Eur J Neurosci. 2021 Sep;54(5):5687-5704. doi: 10.1111/ejn.14781. Epub 2020 Jun 8.
Semipalmated sandpiper (Calidris pusilla) migration to the Southern Hemisphere includes a 5-day non-stop flight over the Atlantic Ocean, whereas semipalmated plover (Charadrius semipalmatus) migration, to the same area, is largely over land, with stopovers for feeding and rest. We compared the number and 3D morphology of hippocampal astrocytes of Ch. semipalmatus before and after autumnal migration with those of C. pusilla to test the hypothesis that the contrasting migratory flights of these species could differentially shape hippocampal astrocyte number and morphology. We captured individuals from both species in the Bay of Fundy (Canada) and in the coastal region of Bragança (Brazil) and processed their brains for selective GFAP immunolabeling of astrocytes. Hierarchical cluster analysis of astrocyte morphological features distinguished two families of morphological phenotypes, named type I and type II, which were differentially affected after migratory flights. Stereological counts of hippocampal astrocytes demonstrated that the number of astrocytes decreased significantly in C. pusilla, but did not change in Ch. semipalmatus. In addition, C. pusilla and Ch. semipalmatus hippocampal astrocyte morphological features were differentially affected after autumnal migration. We evaluated whether astrocyte morphometric variables were influenced by phylogenetic differences between C. pusilla and Ch. semipalmatus, using phylogenetically independent contrast approach, and phylogenetic trees generated by nuclear and mitochondrial markers. Our findings suggest that phylogenetic differences do not explain the results and that contrasting long-distance migratory flights shape plasticity of type I and type II astrocytes in different ways, which may imply distinct physiological roles for these cells.
斑胸滨鹬（Calidris pusilla）向南半球的迁徙包括连续 5 天不停歇地飞越大西洋，而斑胸滨鹬（Charadrius semipalmatus）向同一地区的迁徙则主要在陆地上进行，中途会停下来觅食和休息。我们比较了秋季迁徙前后斑胸滨鹬和斑胸滨鹬的海马星形胶质细胞的数量和 3D 形态，以检验以下假设：这两个物种截然不同的迁徙飞行方式可能会对海马星形胶质细胞的数量和形态产生不同的影响。我们在芬迪湾（加拿大）和布拉干萨（巴西）的沿海地区捕获了这两个物种的个体，并对其大脑进行了选择性 GFAP 免疫标记星形胶质细胞。星形胶质细胞形态特征的层次聚类分析将两种形态表型家族区分开来，分别命名为 I 型和 II 型，这两种表型在迁徙后受到不同的影响。海马星形胶质细胞的体视学计数表明，斑胸滨鹬的星形胶质细胞数量显著减少，但斑胸滨鹬的数量没有变化。此外，斑胸滨鹬和斑胸滨鹬的海马星形胶质细胞形态特征在秋季迁徙后受到不同的影响。我们使用核和线粒体标记物生成的系统发育树，通过系统发育独立对比方法评估了形态测量变量是否受到斑胸滨鹬和斑胸滨鹬之间系统发育差异的影响。我们的研究结果表明，系统发育差异并不能解释结果，而对比长距离迁徙飞行以不同的方式塑造了 I 型和 II 型星形胶质细胞的可塑性，这可能意味着这些细胞具有不同的生理功能。
