The BRAIN-project is an endeavor in using computer aided learning to improve the understanding of the human brain anatomy. The project consists of four parts, each based on modular packages: BRAINIMAGES: Brain atlas consisting of horizontal and frontal brain slices spaced I mm apart enabling the identification of structures and areas of the brain. The software also contains views of the brain's outer surface with all pertinent structures marked. BRAINRADIOLOGY: Visualisation of the brain using CT, MRI and angiography. The different imaging techniques enable the user to explore the brain from several angles and also view the major blood vessels of the brain. NEUROHISTOLOGY: Cells of the brain using histologically stained sections. The program emphasizes the organization of cells in layers and the interaction of different cell types. 3D-BRAIN: Three dimensional reconstructions based on physical slices of a human brain. The reconstructed brain views are made interactive using a simple form of desktop virtual reality: QuickTime VR technology. The user can rotate the different views in all directions producing a 3D effect. The different views are designed to highlight important structures and their organization within the outlined (and semi transparent) brain surface. Contrary to similar applications, the actual three dimensional objects are not based on MRI or CT scans (with comparatively poor resolution), but on tracings made on high resolution images of photographs of actual sections of a postmortem brain. N.B., this approach produces 3D renderings in a more detailed and reliable way. The BRAIN project is designed as a support package for students in preclinical education by supplying additional means for gathering information pertinent to the curriculum. By cross linking, the students can switch from a three dimensional object to a corresponding slice, and then to the relevant histological sample and son on. The software components are based on a modular design enabling easy modification of the various parts and the entire project is designed to run on both Apple Macintosh and MS Windows based PCs.