Fluorescence microscopy in optically cleared brains extracted from [68Ga]Ga-TC3-OGDOTA-injected 5xFAD and wild-type mice. (a) [68Ga]Ga-TC3-OGDOTA fluorescence (green) in optically cleared 2-mm wild-type (top) and 5xFAD (bottom) brain sections. The sections were imaged with 1 mm depth and 3D reconstruction was prepared using ImageJ as described in Methods. (b) [68Ga]Ga-TC3-OGDOTA fluorescence in the hippocampus of 5xFAD brains. A coronal section was imaged with 0.3 mm depth and 3D-reconstructed. (c, d) Sections from (a) were stained for amyloid plaques with thioflavin S. (c) Hippocampi of wild-type (top) and 5xFAD (bottom) were imaged for plaques (ThioS, blue) and [68Ga]Ga-TC3-OGDOTA (OG, yellow). (d) Confocal images of 5xFAD brains showing amyloid plaques (white arrows) surrounded by [68Ga]Ga-TC3-OGDOTA-positive objects.