Brain connectivity from micro to macro scale

The mammalian brain is a highly complex organ, with a broad range of regional microscale cellular morphologies and macroscale global properties, together forming an efficient system for processing and integration of multimodal information. Scientists investigating the brain across different species and across scales of observation have reported on a large regional variability in brain organization. For example on the microscale, large variation in cortical microscale cyto-, myelo- and chemoarchitecture has been observed. On the macroscale of corticocortical connectivity, regions have widely differing connectivity profiles with some regions connecting to regions broadly distributed across the cortex, while others have mostly local connections. Variability in both scales of organization has been observed to coincide with differentiated functional roles of cortical regions within the healthy brain, as well as with disease-related biomarkers. How cortical organization on the micro and macroscale interact – and how this interaction influences brain function in disease – remains largely an open question. The work presented in this thesis explores the association between whole-brain patterns of microscale architecture and macroscale region-to-region connectivity.