Wide-Field Montage on Transmission Electron Microscopy via Network Tele-Microscopy Enables Quantitative Analysis of Mouse Olfactory Bulb Neural Circuits

Transmission electron microscopy (TEM) provides nanometer-scale resolution, which is essential for ultrastructural analysis of biological tissue. However, its application for large tissue areas is limited by a restricted field of view and observer-dependent sampling. In this study, we present a workflow that combines wide-field montage TEM-via "network tele-microscopy"-with correlative light and electron microscopy to enable large-area ultrastructural analysis while preserving synapse-level resolution. We demonstrate this approach in the glomerular layer and tyrosine hydroxylase-positive neurons in mouse olfactory bulb glomeruli, which exhibit dense, heterogeneous synaptic organization. Light and confocal laser scanning microscopy was first used for orientation in regions of interest, allowing the generation of continuous wide-field montage TEM datasets. This approach allowed systematic identification and quantification of synapses across an entire glomerulus while maintaining spatial relationships among ultrastructural elements. This study demonstrates a technically feasible platform for the development of TEM and the future integration of network tele-microscopy with computational methods.