The Virtual RatBrain Project formed in 2004 in order to build a repository of peer reviewed 3-D cellular anatomical data of the rat brain, collected at multiple levels and from multiple brain regions, including point-to-point coordinate connections, cell populations of different neurochemical phenotype and dendritic and axonal arborizational patterns. We have developed a centralized database that contains digitized 3-D vectorial data that are integrated into a standardized coordinate space ("Virtual RatBrain"). This database can be accessed by our tools which allow users to visualize and analyse this evolving 3-D dataset. The analytical tools include the investigation of density information, as well as, topological association pattern of different cell populations (convergence and divergence), and 3-D analysis of dendritic and axonal morphometry... >>  http://www.ratbrain.org