Journal: Nature Neuroscience

Article Title: A suite of engineered mice for interrogating psychedelic drug actions

doi: 10.1038/s41593-026-02375-0

Figure Lengend Snippet: a , Schema of genetic modifications in exon 3 of the mouse Htr2a gene. For the Htr2a EGFP-CreERT2 mouse line, EGFP was inserted after H452 into the CT of the receptor. An IRES-CreERT2 cassette was inserted between the Htr2a stop codon and the 3′ UTR. Light blue boxes represent exons of mouse Htr2a , the green box represents EGFP, and the red box represents the stop codon. The brown and pink boxes are IRES and CreERT2, respectively. b , Validation of Egfp and Htr2a mRNA expression in the mouse brain. RNAscope experiments were performed to probe Egfp and Htr2a mRNA expression in C57 and Htr2a EGFP-CreERT2/EGFP-CreERT2 mice. The Htr2a (red) probe was detected in C57 mice. The Egfp (green) and Htr2a (red) probes colocalized (yellow) in Htr2a EGFP-CreERT2/EGFP-CreERT2 mice. c , Sequential brain sections through the frontal cortex area were used to visualize the distribution of HTR2A-EGFP-CT in the mPFC. AChE staining was present in the dorsal prelimbic cortex, while absent in the ventral prelimbic and infralimbic cortices. The red arrow indicates the boundary between the dorsal and ventral prelimbic cortices. HTR2A-EGFP-CT was present in the dorsal prelimbic cortex, but a much lower AChE staining intensity was observed in the ventral prelimbic and infralimbic cortices; ACC, anterior cingulate cortex; IL, infralimbic cortex; MOp, primary motor cortex; MOs, secondary motor cortex; PL, prelimbic cortex. d , Expression pattern of HTR2A in cortical pyramidal neurons (soma, apical dendrite and apical tuft). e , Distribution pattern of HTR2A-EGFP-CT labeling in the dorsal striatum (caudate putamen). MOR was enriched in striosomes, including the subcallosal stria. HTR2A-EGFP-CT overlapped with the MOR distribution. Note, all brain sections in c – e from Htr2a +/EGFP-CreERT2 mice were co-stained with anti-GFP for HTR2A-EGFP-CT and other markers. Experiments were conducted with three mice with similar results. Images were acquired using an Olympus VS120 slide scanner with a ×10 objective or an Olympus confocal microscope under a ×60 objective. Schematic in a created in BioRender; Chiu, Y. https://biorender.com/97s8x6p (2026).

Article Snippet: The RNAscope experiment followed the manufacturer’s protocol (RNAscope Multiplex Fluorescent Reagent Kit v2 assay, Advanced Cell Diagnostics Bio) with slight modifications.

Techniques: Biomarker Discovery, Expressing, RNAscope, Staining, Labeling, Microscopy