Brain atlases can provide a lot of information about the anatomy of the human brain. However, understanding the shapes of regions and the overall hierarchical structure of a brain atlas can be difficult. Brain atlases contain hundreds of regions with shapes which are hard to distinguish. The transformations of those shapes make them very difficult to visualize because the brain regions are usually packed tightly together and occlude each other. This thesis presents a visualization system based on virtual reality interactions. It enables interactive exploration of brain atlases and an underlying medical image by creating exploded views using VR technology to enhance the visualization of the brain medical atlas. It also integrates a neuronal connectivity visualization approach to show the relations among atlas regions.