The Takahashi Laboratory conducts research on a variety of problems in brain development and neuroscience. One line of research concerns typical and atypical development of brain connectivity and gyral formation ranging from fetal to young adult ages. Results collected over the past years in normal fetal samples and healthy newborns/infants suggest that diffusion MRI tractography can detect migratory pathways and emerging axonal connectivity in the preterm brain as early as 15 gestational weeks. Regional variations of developmental speed of different types of axonal pathways and their relationships to gyral formation can also be detected in a 3-dimensional manner.
A second theme of the Takahashi Lab is concerned with optimization of diffusion MRI tractography across brain regions, types of axonal tracts, and in pathologic tissues. One of the major remaining challenges of diffusion MR tractography is to determine optimal fiber reconstruction parameters in different brain regions. It is essential to find optimal fiber reconstruction settings in each brain region, as well as optimal combinations of such parameters across brain regions in order to significantly increase the imaging accuracy of whole brain fiber pathways. Such optimal parameters can also vary in developing brains depending on the degree of myelination. We therefore need to optimize and utilize diffusion MRI tractography to accurately image 3-dimensional fiber trajectories.
A third theme of the lab is to accurately determine the time course of development of brain connectivity in mouse and human whole brains in normal states and with developmental brain disorders using optimized parameters. We have been studying rodent models of developmental brain disorders that are highly associated with mild to severe brain malformations also with disturbances of development of axonal pathways. We will have broad opportunities to apply this line of technique to a number of transgenic disease models and patient populations including axonal degeneration, myelination/neuronal migration problems, and other neurological and psychiatric disorders.
A final, important theme of the lab is concerned with comparisons of brain development across species. Based on the assumption that the neural architecture underlying human brain functions is a consequence of unique developmental processes in humans, we have identified multiple types of brain pathways linked to specific brain functions and compared their developmental time-courses and connectional patterns across species to better understand human brain development.