Functional and multiscale 3D structural investigation of bra

yet acquiring volumes containing full mammalian neural circuits is challenging and time consuming using EM. Here， combining functional measurements with multiscale X-ray microscopy and volume EM establishes a correlative workflow that enables functional and structural investigation of subcellular features in the context of cellular morphologies， for up to 350 μm. Correlating EM with SXRT allowed us to associate dendritic spines on pyramidal cell apical dendrites in the stratum radiatum to their corresponding soma locations. Superficial pyramidal neurons had larger spine apparatus density compared to deeper ones， Attributing in vivo neurophysiology to the brains’ ultrastructure requires a large field of view containing contextual anatomy. Electron microscopy (EM) is the gold standard technique to identify ultrastructure， tissues and ultimately whole organs. ， we show that X-ray tomography and volume EM can be reliably correlated to prior in vivo imaging. Thus， we show that synchrotron X-ray computed tomography (SXRT) provides rapid imaging of EM-prepared tissue volumes of several cubic millimetres. Resolution was sufficient for distinguishing cell bodies as well as for tracing apical dendrites in olfactory bulb and hippocampus， implying differential synaptic plasticity for superficial and deeper cells. Finally，。