Multimodal Multiscale Microscopic Imaging of the Brain: Revealing Secrets Hiding in Plain Sight

New contrasting methods, imaging tools, and data analysis strategies allow the observation of otherwise complex or hidden relationships between cellular, subcellular, and molecular constituents of cells and tissues. I will describe how advances in multi-tilt electron tomography, the development of new probes for correlated light microscopy, X-ray micro-CT, correlated multi-ion mass spectroscopy imaging and electron microscopy, and state-of-the-art 3D EM technologies add to our knowledge of structure and function in complex biological systems. Recent accomplishments include the determination of the higher-order structure and functional organization of chromatin in intact cell nuclei; the analysis of actin-associated structures within dendritic spines; and analyses of the extracellular matrix (ECM) around multiple synapse types in mammalian brains. The ECM work explores Roger Tsien’s theory that the brain stores life-long memories by regulating the activity of extracellular proteases and thereby influences the locations and relative strengths of synapses over a lifespan.