Frank Moore - US grants

The long-term goal is to identify the physiological functions of the peptide hormones which control reproductive behaviors. Recent research demonstrates that the reproductive behaviors of certain animals can be influenced by injections of any of the following peptide hormones: luteinizing hormone-releasing hormone (LHRH), adrenocorticotropin (ACTH), arg vasotocin (AVT), prolactin and endorphin. But the specific actions and interactions of these peptides in modulating reproductive behaviors remain unknown. The proposed research will use the extirpation-replacement experimental paradigm, microinjections of hormones or their antagonists into specific regions of the brain, and measurement of endogenous concentrations by radioimmunoassay procedures. These studies will determine the functional relationships between the gonadal steroid hormones (e.g. estradiol and dihydrotestosterone) and the peptides listed above. Other experiments will identify the functional relationships among the peptides, determining for example, whether AVT enhances the behaviors by causing a localized release of LHRH. Many gaps in our understanding of the neurochemical pathways which control the propensity to exhibit reproductive behaviors will be filled by these studies. The specific behavior for study will be the reproductive behavior of a species of urodele amphibian. The simplified nervous system of amphibians, the stereotyped nature of their reproductive behavior, and the recent evidence from my laboratory indicating that the same hormones that modify the reproductive behaviors of mammals also modify behaviors of this amphibian makes this animal an advantageous research model.

Stress, aggression, and reproduction are examples of behaviors that are affected by steroid hormones. Recently, it has become clear that another class of hormones, called neuropeptides, have major effects on behaviors. Dr. Moore will investigate the mechanisms by which steroid hormones and neuropeptides interact in the brain to regulate behavior. He will employ modern anatomical and molecular techniques to determine the effects of gonadal steroid hormones on the neuropeptide, arginine vasotocin, in a simple amphibian model system. By quantifying vasotocin receptors in neurons, measuring vasotocin concentrations in behaviorally important brain areas, and determining the activity of vasotocin genes in individual brain cells, Dr. Moore will determine whether seasonal changes or sexual differences in the vasotocinergic system are associated with the behavioral state and whether gonadal steroid hormones that maintain reproductive behaviors influence this neuropeptide system. These studies are possible because of the reduced structural complexity of the amphibian brain in combination with their distinct stereotyped responses to neuroendocrine manipulations. Insights gained with this model system will lay the groundwork in understanding of the functional relationship between steroid hormones and neuropeptides in animals with much greater complexity.

Long-distance migration is an integral part of the life history of many animals, including over half of all North American landbirds. The mortality associated with migration is substantial, and yearling migrants suffer greater mortality than adult individuals. This research project compares the behavioral ecology of yearling and adult Neotropical landbird migrants and examines the consequences of age in relation to how migrants meet the energy demands of migration. Many of the adaptations that have evolved in association with long-distance migration are critical when birds must cross geographic barriers. Hence, the best place and time to study the stopover ecology of Neotropical landbird migrants is immediately before or after they cross the Gulf of Mexico. Study sites along the northern Gulf coast provide a unique opportunity to work with populations of migratory species. Habitat loss is one of the most critical ecological problems associated with global environmental change. The degree and timing of these large-scale effects can have significant ecological repercussions that are hard to measure unless one can assess each stage of a species' life cycle. Dr Moore's research into the critical stopover stage promises new insight into species-level effects of higher-order ecological dynamics. Decline in populations of Neotropical landbird migrants is a serious conservation problem; one linked to habitat loss on the wintering grounds and fragmentation of forested breeding habitat. The status of migrant populations is also affected by the availability of suitable stopover habitat and the response of migrants to en route events. Consequently, factors associated with the stopover biology of migrants must figure in any analysis of population change and in the development of a comprehensive conservation "strategy" for Neotropical landbird migrants. The current research project combines observational and experimental studies to compare stopover biology of yearling and adult birds and should contribute measurably to the conservation of Neotropical landbird migrants.

An unprecedented loss of the variety and numbers of plant and animals species around the world is occurring. Habitat destruction, over-harvesting, chemical pollution, introduced exotic species, and climatic change are among the major threats to living species. In particular, many species of amphibians are undergoing drastic population declines and range reductions. The amphibian declines are especially perplexing because many species are disappearing in pristine habitats. Atmospheric factors, perhaps acting with other agents, may be contributing to the declines. Using amphibians, Dr. Blaustein and his colleagues propose to investigate one potential atmospheric source of biological trauma, ultraviolet radiation (UV), that may have significant biological effects ultimately contributing to population declines. Amphibians are excellent "bioindicators" of environmental change, due in part to their relatively thin, permeable and unprotected skin. The decline in amphibians may be an early warning signal and ultimately, other organisms, including humans, may be in peril. Results should yield information with broad implications regarding the potential for atmospheric effects on other organisms. The investigation will be focused at several levels of biological organization including molecular, individual, and population levels. Laboratory and field experiments will examine the effects of natural levels of UV on developing tadpoles and on the reproductive physiology of adult frogs. How UV-damaged DNA is repaired will also be examined. An ecological survey of declining species will be conducted to document their overall population status. This is one of the first studies to incorporate field experiments to investigate the effects of UV on development in wild vertebrates. Since conditions likely to promote increased UV are becoming manifest, it is important to examine whether natural levels of UV have begun to affect the more sensitive animals, like amphibians, so that steps can be taken to reduce a potentially serious environmental threat.

Habitat use during migration has profound consequences for a bird's ability to satisfy energy requirements, vulnerability to predators, and exposure to environmental stress. The proposed research quantifies habitat use during spring and fall en route periods. Presumably migrants select particular habitats because they thereby enhance their fitness. Although it would be difficult to measure directly the effect of en route use of habitat on survival and reproductive success, it is possible to evaluate the immediate consequences in relation to how effectively migrants satisfy energy demand during migration, i.e. deposit fat reserves and gain body mass. Over half of all North American landbirds are long-distance migrants that journey between temperature breeding ranges and more tropical wintering areas. Decline in populations of Neotropical landbird migrants is linked to habitat loss on the wintering grounds and fragmentation of forested breeding habitats. Because the persistence of migrant populations depends on the bird's ability to find favorable conditions throughout the annual cycle, factors associated with the en route ecology of migrants must figure in the formulation of sound conservation policy.

This award is to provide some travel support for the participants of symposium entitled "Strategies for Analyzing Neuropeptide Systems" to be held at the annual meeting of American Society of Zoologists, December 27th to 30th, 1991, in Atlanta, Georgia. The focus of the symposium is on cellular and molecular approaches associated with neuropeptide systems. The aim is to provide a broad comparative scope and stress the applications of these valuable techniques for the specific needs of the diverse audience that attends this meeting. A roundtable discussion following the presentations will be used to evaluate and integrate the research strategies presented by the speakers. The participants represent a group of young investigators who are directly active in the research and are establishing their own outstanding careers in this rapidly advancing area of neurobiology. The proceedings of the symposium will be published in the American Zoologist and, thus, accessible to scientists that did not attend this meeting but would benefit from a review of the state-of-the-art approaches and techniques available to tackle important biological problems. Finally, this symposium will be used to test the feasibility of forming a multidisciplinary division of neuroscience within the American Society of Zoologists.

Corticosteroids control many brain functions and behaviors, including adaptive responses to acute stress resulting from social, environmental, or physiological challenges. Some of these corticosteroid responses occur very rapidly--within seconds for changes in intracellular ions and second messengers, or within a few minutes for changes in secretions and behaviors. These responses are too rapid to be easily explained by the classic genomic model for steroid action. Instead they suggest there may be alternative, non-genomic signaling pathways. Our research in an amphibian demonstrated that a membrane receptor for corticosteroids exists in neuronal membranes. Based on pharmacological responses, the receptor appears to be in the G protein-coupled receptor (GPCR) superfamily. Opioid receptors, another member of GPCR family, also play important roles in regulating brain functions and behaviors in response to acute stress. For a number of reasons, including recent data showing that a subset of kappa-selective opioid ligands bind to the membrane corticosteroid receptor, we suggest that the membrane corticosteroid receptor is structurally related to the kappa opioid receptor and orphan opioid-like receptor. As a first step toward discovering the molecular identity of the membrane receptor for corticosteroids, this research project will conduct research on opioid-like receptors in an amphibian research model. Behavioral studies, ligand-binding assays, and molecular techniques will be used to better understand the structure and functional relationship between the membrane corticosteroid receptor and the opioid-like receptors. There are four parts to the research project: first, the binding site selectivity for corticosteroids and opioids will be characterized. Second, behavioral tests will determine the relative potencies of sufficiently selective steroids and opioids to inhibit male sexual behaviors. Third, cDNAs that encode for the opioid-like receptor proteins will be isolated and cloned. Fourth, ligand selectivity for the binding sites in transiently expressed opioid-like receptors will be characterized. These studies will provide information, for the first time in any species, about the convergence in receptor mechanisms for corticosteroids and dynorphin peptides. The studies also might reveal the molecular identity of a membrane receptor for corticosteroids.

Measuring and describing patterns of individual and population movement is a fundamental aspect of understanding the physiology, behavior, ecology and life-history of any animal. Measuring movement also can provide the key to predicting species extinctions and invasions or the spread of disease. Yet, we have long been limited in our abilities to track animal movements over large distances and across time. Following individual animals has always proven challenging for human observers. Researchers must rely on technological innovations to expand our abilities to measure and describe movement. Recent rapid advances in molecular, chemical, electrical, and remote-sensing technologies are creating new tools for tracking individuals and whole populations and opening new frontiers for ecologists by allowing us to follow small, highly mobile animals like migratory songbirds in real-time across continents. The MIGRATE Research Coordination Network (RCN) will bring together researchers who are pioneering the development and application of emerging technologies for the purpose of investigating the amazing long-distance movements of migratory songbirds.
Long-distance landbird migration is an ideal system for applying new technologies in ways that advance both the technologies and our ability to describe movement strategies. To accelerate progress in these areas, the MIGRATE network will: (1) focus research techniques and questions on a small suite of model species that will advance understanding of ecological and evolutionary implications of long-distance movement; (2) foster cross-disciplinary collaborations among researchers throughout the Americas and Europe; (3) encourage standardized collection and sharing of tissues, technological advances, and data; and (4) create a platform for interdisciplinary training of students and the public. Additionally, by working at the nexus of emerging technologies (e.g., molecular, electrical, remote-sensing) and ecology, this network will provide allow currently active researchers to engage students from groups under-represented in the sciences in novel research projects.
Application of emerging intrinsic and extrinsic tracking technologies to novel problems in ecology will improve the technologies themselves. The rigorous research fostered by MIGRATE will increase our ability to identify population-level sources of DNA, stable isotope ratios, and trace elements. Advances in use of molecular markers will have applications across a broad range of disciplines such as identifying sources of bio-terrorism, commercial testing of ingredient purity, and locating origins of introduced exotic species. MIGRATE will allow students to access the newest developments, make field scientists aware of state-of-the-art technology advancements, and provide an interface between industry and field ecologist in diverse countries. In areas of health and economics, the results of MIGRATE can be applied to understanding and controlling the spread of disease through animal movement. Moreover, the ability to track individual migrant birds and identify populations will have immediate applications for conservation planning. A complete and integrated understanding of migration ecology will allow for more effective use of limited conservation resources and provide scientists with the ability to use migratory birds to monitor ecological responses to global climate change. This network will bring together a diverse set of approaches, facilitating communication among researchers on a multinational, inter-continental scale.

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).

Migration is a fundamental characteristic of the life history of many organisms allowing individuals to take advantage of different habitats as environments change seasonally. For example, over two-thirds of all landbirds that breed in temperate North America fly thousands of kilometers to nonbreeding areas in Central and South America. Traveling long distances is energetically expensive, and the mortality associated with migration is thought to be substantial. How well a bird solves problems that arise during migration determines the success of migration, and ultimately a bird's survival. That said, following individuals throughout the year poses a serious challenge, and our understanding of the behavior of migrating birds has been constrained by not knowing the bird's breeding destination, not to mention the point of departure. Information from stable isotopes, genetic markers, and plumage coloration is integrated to geographically link individual birds captured at stopover sites in the southern U.S. during spring migration with their ultimate breeding destination in North America. This novel approach will allow a more comprehensive understanding of the strategies used by birds during migration. For example, do birds 'late' on their migration stop over for a shorter time and do they redeposit critical energy stores faster than migrants on schedule? Do late migrants 'catch up' by migrating faster or for more hours once aloft? This project will enhance not only understanding of the behavior, ecology, and evolution of migratory birds, but also development of conservation strategies for animals whose annual cycle bridges continents. The project continues a long history of undergraduate and graduate student traineeship and, because of the dramatic nature of animal migration, provides rich opportunities for outreach to educational groups and the community.

Migration is a fundamental characteristic of the life history of many organisms. Over two-thirds of all the songbirds that breed in temperate North America move long distances to non-breeding areas in Mexico, Central and South America, and the islands of the Caribbean. This project will support a critical synthesis of field and laboratory research since the early 1980s on the biology of migrating birds. The foci of the work will be the challenges migrants face when they stop over during migration, how migrants contend with those challenges, and the consequences of their response to en route challenges, the sum of which determine the success of migrations. Two synthetic products will be created: a book and a complementary set of audio-visual (A-V), internet-accessible presentations designed for educational use and outreach. Synthesis of this large body of research is especially important now, as changing global climate may challenge organismal adaptations that have been successful in the past.

This project will advance understanding of migration and will reach beyond the scientific community by way of informal science education. The biology of migrating birds us attractive for science education and for making connections with nature. The two, related products will be widely accessible to students and the scientific community, and the set of internet-accessible, downloadable A-V presentations will be designed to be accessible by and attractive to a broader public audience. The A-V presentations will focus on how migratory birds respond to the challenges that arise during stopover, will be made available through a web interface, and will be freely available for educational purposes.

Many animals migrate during specific periods of the year, moving between wintering and breeding locations. Specifically this research will test the role of overwintering habitat quality in the timing of migration initiation, duration of migration and arrival at the breeding area, as well as ability of Black-and-white-warblers to compensate for the quality of the overwintering habitat while stopping at refugia to refuel during migration. This research will link the timing and distance of migration to subsequent reproductive success during the breeding period and ability to successfully survive the winter using the presence of stable isotopes in feathers and amount of plasma metabolites to quantify an individual's condition. Information about the activity at the stopover areas will allow assessment of the carry-over of nutrients and condition between breeding, migration and overwintering and the integration of all phases of the annual life history cycle. These data will enhance our understanding of how the different phases of an individual's life cycle influence each other. In addition, the project will also provide cross-disciplinary biological training for graduate and undergraduate students from underrepresented groups.

Approximately two-thirds of all songbird species that breed in eastern North America migrate to tropical areas for the winter, requiring most species to cross the Gulf of Mexico. Flights across the gulf are considered hazardous and may result in mass mortality. Atmospheric conditions over water, as well as characteristics of the birds themselves (e.g., age, physical condition), are likely important predictors of birds' migratory routes and survival. However, most knowledge about when, where and how small birds cross large water bodies and their survival remains speculative, because until now researchers have been unable to track individuals between the start and end points of over water flights. Anticipated changes in atmospheric structure and dynamics caused by climate change urgently require an understanding of how migrating birds interact with the atmosphere. This knowledge will provide insight to potential consequences of climate change on migratory songbirds, many of which are experiencing population declines. Knowledge of animal-atmosphere relationships is timely as wind energy development accelerates and coastal habitat alteration along migratory flyways continues. The interdisciplinary research team will combine modern radio telemetry and favorable geography to document migratory flights of songbirds across the gulf. By integrating field data, atmospheric data and computational simulations and analyses, the team will provide the first estimate of songbird survival during migration across open water. They also will study factors shaping birds' migratory routes and timing. The team will promote learning, excitement and appreciation for science, and animal migration in particular, to non-scientists through educational materials (e.g., animated migration trajectories in Google Earth©). The team will disseminate findings to scientists, reserve managers and the general public via presentations, publications, a bilingual project website, and popular media. American and Latino undergraduate and graduate students and post-doctoral researchers will participate in each phase of research to acquire learning and skill-building opportunities.