Hippocampal neurogenesis and volume in migrating and wintering semipalmated sandpipers (Calidris pusilla)

• Published in: PloS one Vol. 12; no. 6; p. e0179134
• Main Authors: de Morais Magalhães, Nara Gyzely, Guerreiro Diniz, Cristovam, Guerreiro Diniz, Daniel, Pereira Henrique, Ediely, Corrêa Pereira, Patrick Douglas, Matos Moraes, Isis Ananda, Damasceno de Melo, Mauro André, Sherry, David Francis, Wanderley Picanço Diniz, Cristovam
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 07-06-2017; Public Library of Science (PLoS)
• Subjects: Alaska; Analysis; Animal Migration - physiology; Animals; Atlantic Ocean; Biology and Life Sciences; Bird migration; Birds; Brain; Brain research; Brazil; Breeding; Canada; Cell growth; Charadriiformes - growth & development; Coastal zone; Cognitive ability; Cues; Detection; Doublecortin protein; Enrichment; Exercise; Feeding Behavior; Flight; Hippocampus; Hippocampus - growth & development; Medicine and Health Sciences; Memory; Migratory animals; Migratory birds; Neurogenesis; Neurogenesis - physiology; Neurons; Neurosciences; Physical fitness; Physical training; Polar environments; Psychological aspects; Rodents; Sandpipers; Seasons; Sensory integration; Spatial analysis; Stress; Stresses; Tundra; Windows (intervals); Canada; Bay of Fundy
• DOI: 10.1371/journal.pone.0179134
• EISSN: 1932-6203

Long distance migratory birds find their way by sensing and integrating information from a large number of cues in their environment. These cues are essential to navigate over thousands of kilometers and reach the same breeding, stopover, and wintering sites every year. The semipalmated sandpiper (Calidris pusilla) is a long-distance migrant that breeds in the arctic tundra of Canada and Alaska and winters on the northeast coast of South America. Its fall migration includes a 5,300-kilometer nonstop flight over the Atlantic Ocean. The avian hippocampus has been proposed to play a central role in the integration of multisensory spatial information for navigation. Hippocampal neurogenesis may contribute to hippocampal function and a variety of factors including cognitive activity, exercise, enrichment, diet and stress influence neurogenesis in the hippocampus. We quantified hippocampal neurogenesis and volume in adult migrating and wintering semipalmated sandpipers using stereological counts of doublecortin (DCX) immunolabeled immature neurons. We found that birds captured in the coastal region of Bragança, Brazil during the wintering period had more DCX positive neurons and larger volume in the hippocampus than individuals captured in the Bay of Fundy, Canada during fall migration. We also estimate the number of NeuN immunolabeled cells in migrating and wintering birds and found no significant differences between them. These findings suggest that, at this time window, neurogenesis just replaced neurons that might be lost during the transatlantic flight. Our findings also show that in active fall migrating birds, a lower level of adult hippocampal neurogenesis is associated with a smaller hippocampal formation. High levels of adult hippocampal neurogenesis and a larger hippocampal formation found in wintering birds may be late occurring effects of long distance migratory flight or the result of conditions the birds experienced while wintering.