Contrasting migratory journeys and changes in hippocampal astrocyte morphology in shorebirds

Edital Universal Grant number 440722/2014-4/Brazilian Research Council (CNPq) Programa de Apoio a N?cleos Emergentes - Centro de Piscicultura do IFPA Campus Bragan?a/Funda??o Amaz?nia Paraense de Amparo ? Pesquisa (FAPESPA) Canada-Brazil Awards - Joint Research Projects (/The Canadian Bureau for International Education (CBIE) Instituto Brasileiro de Neuroci?ncias (IBNnet)/Financiadora de Estudos e Projetos (FINEP) Natural Sciences and Engineering Research Council of Canada Instituto Federal de Educa??o Ci?ncia e Tecnologia do Par? - Campus Bragan?a. Laborat?rio de Biologia Molecular e Neuroecologia. Bragan?a, PA, Brazil. Universidade Federal do Par?. Instituto de Ci?ncias Biol?gicas. Hospital Universit?rio Jo?o de Barros Barreto. Laborat?rio de Investiga??es em Neurodegenera??o e Infec??o. Bel?m, PA, Brazil. Universidade Federal do Par?. Instituto de Ci?ncias Biol?gicas. Hospital Universit?rio Jo?o de Barros Barreto. Laborat?rio de Investiga??es em Neurodegenera??o e Infec??o. Bel?m, PA, Brazil. Instituto Federal de Educa??o Ci?ncia e Tecnologia do Par? - Campus Bragan?a. Laborat?rio de Biologia Molecular e Neuroecologia. Bragan?a, PA, Brazil. Universidade Federal do Par?. Museu Paraense Em?lio Goeldi. Curso de P?s-Gradua??o em Zoologia. Bel?m, PA, Brazil. Instituto Federal de Educa??o Ci?ncia e Tecnologia do Par? - Campus Bragan?a. Laborat?rio de Biologia Molecular e Neuroecologia. Bragan?a, PA, Brazil. Universidade Federal do Par?. Instituto de Ci?ncias Biol?gicas. Hospital Universit?rio Jo?o de Barros Barreto. Laborat?rio de Investiga??es em Neurodegenera??o e Infec??o. Bel?m, PA, Brazil. Instituto Federal de Educa??o Ci?ncia e Tecnologia do Par? - Campus Bragan?a. Laborat?rio de Biologia Molecular e Neuroecologia. Bragan?a, PA, Brazil. Universidade Federal do Par?. Instituto de Estudos Costeiros. Bragan?a, PA, Brazil. Universidade Federal do Par?. Instituto de Estudos Costeiros. Bragan?a, PA, Brazil. Instituto Federal de Educa??o Ci?ncia e Tecnologia do Par? - Campus Bragan?a. Laborat?rio de Biologia Molecular e Neuroecologia. Bragan?a, PA, Brazil. Universidade Federal do Par?. Instituto de Ci?ncias Biol?gicas. Hospital Universit?rio Jo?o de Barros Barreto. Laborat?rio de Investiga??es em Neurodegenera??o e Infec??o. Bel?m, PA, Brazil / Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Laborat?rio de Miscroscopia Eletr?nica. Ananindeua, PA, Brasil. Instituto Federal de Educa??o Ci?ncia e Tecnologia do Par? - Campus Bragan?a. Laborat?rio de Biologia Molecular e Neuroecologia. Bragan?a, PA, Brazil. University of Western Ontario. Department of Psychology, Advanced Facility for Avian Research. London, ON, Canada. Universidade Federal do Par?. Instituto de Ci?ncias Biol?gicas. Hospital Universit?rio Jo?o de Barros Barreto. Laborat?rio de Investiga??es em Neurodegenera??o e Infec??o. Bel?m, PA, Brazil. Instituto Federal de Educa??o Ci?ncia e Tecnologia do Par? - Campus Bragan?a. Laborat?rio de Biologia Molecular e Neuroecologia. Bragan?a, PA, Brazil. 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 Bragan?a (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.