International Research Fellowship Program: Neuroendocrine Adaptations to Stress in Passerines of the Tibetan Plateau

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0701325DavisThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support an eighteen-month research fellowship by Dr. Jason Davis to work with Dr. Lei Fu-Min, Chinese Academy of Science, Institute of Zoology in Beijing, China and with Dr. John Wingfield, University of California, Davis. In climatically extreme environments, animals must regularly alter brain function and behavior in order to survive and reproduce. One of the most important dimensions in which such adaptation can occur is stress neurophysiology. Previous work exploring neuroendocrine correlates of stress responsivity in birds breeding in Arctic and alpine habitats has revealed that such species often dynamically modulate responses to stress through alteration of several neuroendocrine "flex points," allowing them to adaptively minimize or maximize responses to cope with harsh climatic conditions, while at the same time successfully breeding and rearing young. Though there has been substantial exploration of the neurophysiology of such extreme climate breeders, much less is known about the neurophysiology of birds that both breed and winter in one of the planet's most inhospitable and extraordinary environments - the Tibetan Plateau. This project will explore and address behavioral and neuroendocrine correlates of stress sensitivity in passerine birds inhabiting the northern areas of the Tibetan Plateau. This location provides a unique opportunity to study stress adaptation in songbirds, in part because of its isolation and harsh climatic conditions and also its sensitivity to global climate change, but also because many species of birds native to this area do not migrate south during the winter months. Very little is known as to how these species survive in the winter, and how they differ from migratory and lower-altitude invasive species, particularly in regards to stress neurophysiology. In the course of this project, we will take tissue and plasma samples from a number of endemic Tibetan species from several populations and locations on the plateau, during the winter, early summer, and late summer for analysis in relation to corticosterone sensitivity and glucocorticoid receptor density, as well as additional morphological, behavioral and physiological measures. In addition, a number of captured birds will be transferred to a Chinese Ministry of Science aviary facility on the plateau, allowing us to experimentally modulate temperature and climatic conditions as well as to artificially modulate corticosterone levels (via non-invasive administration of a topical corticosterone solution), and closely monitor any behavioral or neuroendocrine changes that result from such modulations. This research takes an integrative approach to exploring the interactions of environment, ecology, physiology and behavior, with a special emphasis on a geographic area of unique value.