Trygve Leergaard is Associate Professor of neuroscience at the Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway. He received his M.D in 1996 (Univ Leiden, The Netherlands) and obtained his Ph.D. degree in neuroanatomy in 2000 (Univ Oslo, Norway). His research has been focused on resolving fundamental architectonical principles underlying brain map transformations in major sensorimotor projection systems connecting the cerebral cortex with several brain stem nuclei. The methodological repertoire includes basic electrophysiological brain mapping, axonal tracing techniques, computerized methods for 3-D reconstruction, visualization and quantitative analysis, immunohistochemistry, histological and microscopy techniques for brain atlasing, as well as high-resolution magnetic resonance imaging for structural brain atlasing and tractography. Important scientific advances include resolving of 3-D architectonic principles of topographic organization in the rat corticopontine system, as well as tonotopic organization in cat ascending auditory pathways. Other activities include multidisciplinary investigation of neural network changes in a transgenic rat model of Huntingtons disease, 3-D digital brain atlasing efforts (combined histological and tomographic approaches), in vivo tracing of brain connectivity using Mn2+ enhanced MRI and diffusion tensor imaging (DTI), neuroanatomical mapping of molecular distribution patterns in transgenic animal models, and high resolution anatomical investigations of rat cerebro-cerebellar networks (single axon tracing technique).