Avian model organisms, including songbirds (zebra finch, canaries, starlings), chicken, quail, and pigeon have contributed much to our understanding of brain function and of disorders that affect neural development, function, and cognition. However, we still lack a clear understanding of how avian brain structures, particularly those that subserve complex learned behaviors and cognition, relate to brain structures in mammals, including humans. It is also unclear how molecular brain specializations of birds relate to those of mammals. To address these gaps, we used funding from the NINDS (R03) and NIGMS (R24) to develop the Zebra finch Brain Expression Atlas (ZEBrA), currently the only in situ hybridization database of brain gene expression for any avian species. ZEBrA is a publicly accessible website that contains >2,200 high resolution digital images of brain sections from adult male zebra finches that are aligned to a reference histological atlas, and hybridized to reveal the expression of >500 genes of relevance for brain development, physiology, plasticity, and learning, including numerous linked to human diseases or to lethal or deleterious phenotypes in rodents. Many of the patterns in ZEBrA reveal differential expression across broad brain subdivisions, previously unsuspected subdomains that cannot be visualized with conventional histology, and high enrichment in nuclei within circuits underlying specific behaviors (e.g., the system that controls vocal production and learning). These patterns have yielded novel insights into molecular specializations of major regions and of specific nuclei, including the discovery of convergent molecular specializations of vocal areas that are shared between songbirds and humans. The availability of ZEBrA has had a large impact (>4,000 users, and 35,000 page views), providing an important source of genetic and neuroanatomical data for a large number of songbird and avian researchers, many funded by the NIDCD, NIMH, NINDS or NICHD. The present proposal aims to use NIGMS's Legacy mechanism to maintain ZEBrA during a transition phase where further funding is sought to ensure the long- term availability, maintenance, and possible future expansion of this unique resource. Such studies will help to further validate the use of avian model organisms for understanding the molecular basis of brain function and disorders. Planned activities consist of regular updates to ZEBrA to ensure links to important databases and compatibility to browsers are kept up-to-date, and addition of 300 already processed genes whose images are not yet available online. Included are also plans for broad dissemination of the resource, close interactions with the community to ensure its needs are met, and evaluation to maximize ZEBrA's utility and impact. Legacy funding will facilitate the transition effort, which includes the preparation of applications to an array of NIH institutes whose stated missions are in line with ZEBrA's goals, and a more limited effort to generate brain expression data for specific genes of interest to individual users but not yet on the database, on a pay for service basis.
Avian species have long been important model organisms for studying brain structure-function relationships and disorders that affect neural development, cognition, and behavior, however a clear understanding of the molecular organization of the avian brain as it relates to mammals has been largely lacking. The Zebra finch Expression Brain Atlas (ZEBrA), a public online in situ hybridization database of brain gene expression and the only such resource for an avian species was built with an R24 from the NIGMS, and has played a crucial role in identifying molecular signatures of major avian brain areas and specialized nuclei, bringing insights into genetic mechanisms of a broad range of processes of high relevance to human brain health and cognition, and neurological disorders. Legacy funding for this application will help maintain ZEBrA as well as implement a transition plan for obtaining additional sources of funding to ensure the long-term availability, maintenance and future expansions of this unique resource.
