Knowledge of neuronal circuitry is foundational to the neurosciences, but no tools have been developed for cataloguing this knowledge. Part of the problem is that the concepts used to describe neural circuits are rapidly evolving and vary substantially across different species. The NeuronBank project (http://neuronbank.org) is developing an informatics infrastructure for managing the dynamic, domain-specific knowledge of neural circuitry, providing a reference source, an outlet for publishing new knowledge, and a useful research tool. Our solution is a federation of customizable knowledge bases, each adaptable to store knowledge of the neural circuitry of a single species. The federation is united by a common set of web services and a central portal that provides core functionality across various knowledge bases. This service-oriented architecture provides domain-specific representations of specialized scientific knowledge while maintaining interoperability across a broad discipline.