US Patent 11419318 Genetically modified rat comprising a humanized

Non-human animal genomes, non-human animal cells, and non-human animals comprising a humanized TRKB locus and methods of making and using such non-human animal genomes, non-human animal cells, and non-human animals are provided. Non-human animal cells or non-human animals comprising a humanized TRKB locus express a human TRKB protein or a chimeric transthyretin protein, fragments of which are from human TRKB. Methods are provided for using such non-human animals comprising a humanized TRKB locus to assess in vivo efficacy of human-TRKB-targeting reagents such as nuclease agents designed to target human TRKB.