Fig. 2.

Virus-labeled histaminergic neurons and downstream circuits in HDC-Arch-GFP^TMN mice. (A) Experimental scheme and timeline for generation of HDC-Arch-GFP^TMN mice. AAV-CAG-FLEX-ArchT-GFP was injected into each side of the TMN of HDC-CreERT2 adult mice. (B) Representative immunohistochemical pictures of expression specificity in HDC-Arch-GFP^TMN mice; GFP and HDC double-positive neurons are indicated by arrowheads. (Scale bars: 50 μm.) (C) Expression specificity analysis of GFP in HDC-Arch-GFP^TMN mice. (D and E) Main steps of data generation, acquisition (D), and processing (E) in fMOST imaging. Raw data were analyzed by NeuroGPS system and manual correction. (Scale bars: 1 mm.) (F) Count numbers of fluorescently labeled neurons in the posterior hypothalamus of HDC-Arch-GFP^TMN mice. (G) The ratio of fluorescent neurons in HDC-Arch-GFP^TMN mice to the number of histaminergic neurons in the whole-brain. (H) Relationship between virus-labeled neurons and whole-brain fluorescent pixels (10 × 10 × 10 μm resolution) from 3 HDC-Arch-GFP^TMN mice. (I) Fluorescent-labeled information visualization of registered HDC-Arch-GFP^TMN mouse brain (Top: sagittal view; Bottom: coronal and horizontal views). (J) Fluorescence fiber density value of various brain regions in 3 HDC-Arch-GFP^TMN mice. Top 35 brain regions in the groups “Dense,” “Moderate,” and “Few” are shown, respectively. See the details and list of abbreviations in SI Appendix, Table S1. All data are presented as mean ± SEM.