Nanoscale imaging of entire intact mouse brains.
(a-b) Intact mouse brains were expanded (3×) and sparsely labeled neurons expressing tdTomato were imaged using the ExA-SPIM microscope ((Ouellette et al. 2023), dx.doi.org/10.17504/protocols.io.n92ldpwjxl5b/v1). (c) Single neurons were traced and reconstructed from the resulting imaging data. (d) Due to a lack of sectioning, stable specimen mounting, fast imaging times, and minimal imaging distortions, adjacent imaging tiles are easily aligned in overlapping regions (Supplementary Videos 1-2). Nanoscale imaging resolves individual dendritic spines (e-h) and axonal varicosities (i-k) with near-isotropic resolution (Supplementary Videos 3-6). Images are displayed as maximum intensity projections with the following thicknesses: (b) 26 mm, (d) 2 mm, (e-h) 1 mm, (i-k), 100 µm.