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Full-Text Articles in Life Sciences
Seasonality Of The Stress Response In House Sparrows (Passer Domesticus)., Michael R. Hasstedt
Seasonality Of The Stress Response In House Sparrows (Passer Domesticus)., Michael R. Hasstedt
Electronic Thesis and Dissertation Repository
Seasonal changes in plasma corticosterone (CORT) levels indicate that birds modify their stress response through the year. Although this has been well documented, the method by which birds achieve this seasonality is not well understood. In this study I used house sparrows to determine if changes in glucocorticoid receptor (GR) immunoreactivity in several stress-related brain nuclei showed seasonal variation. The house sparrowsshowed seasonal variation in their stress response with baseline CORT levels being highest during the breeding season and lowest during winter. There was also significant change in plasma CORT post-dexamethasone during breeding, but not during other times of the …
Seasonal Hippocampal Plasticity In Food-Storing Birds., David F Sherry, Jennifer S Hoshooley
Seasonal Hippocampal Plasticity In Food-Storing Birds., David F Sherry, Jennifer S Hoshooley
Psychology Publications
Both food-storing behaviour and the hippocampus change annually in food-storing birds. Food storing increases substantially in autumn and winter in chickadees and tits, jays and nutcrackers and nuthatches. The total size of the chickadee hippocampus increases in autumn and winter as does the rate of hippocampal neurogenesis. The hippocampus is necessary for accurate cache retrieval in food-storing birds and is much larger in food-storing birds than in non-storing passerines. It therefore seems probable that seasonal change in caching and seasonal change in the hippocampus are causally related. The peak in recruitment of new neurons into the hippocampus occurs before birds …