Journal: bioRxiv

Article Title: The acute sleep-inducing effects of light require histamine neurotransmission in mice

doi: 10.1101/2025.06.26.661495

Figure Lengend Snippet: (A) Schematic of a coronal section of the brainstem showing the location of the TMn. (B) A confocal photomicrograph of lower magnification showing both histidine decarboxylase (HDC (green) and HA-Tag (red) single and double (orange) fluorescent labeling in the TMn and adjacent posterior hypothalamus. (C1-C3) photomicrographs of higher magnification of the boxy insert in B showing the number and morphology of HDC-immunoreactive (-ir, green), HA-Tag positive (red) and dual-labeled (orange) cells in the TMn. Note that a large number of HDC-ir cells are HA-Tag positive, indicating recombination of major histaminergic neurons with hM4Di receptor following crossing between HDC-cre and hM4Di mice. Other abbreviations: 3V, third ventricle, F, fornix. White scale bar =100 μm.

Article Snippet: Floating sections were rinsed in 0.01 M PBS solution containing 0.1% Triton X-100 (PBST) for 10 min × 3 times, then incubated in blocking solution (10.0% fetal bovine serum in 0.01 M PBST) for 1.5 h. Sections were incubated with a rabbit monoclonal antibody against HA-Tag (C29F4) (1:1,000 in blocking solution, #3724, Cell Signaling Technology, Massachusetts, USA) for 24 h at 4 °C.

Techniques: Labeling