For electrophysiology experiments, the tissue block containing the injection site was stored overnight in 10% neutral-buffered formalin at 4°C. After, it was transferred into 0.2% PBS Azide at 4°C until sectioning. The tissue block was mounted onto a stage and sectioned in 0.1M PBS at a thickness of 100μm using a VT-1000 vibratome (Leica). Slices were mounted onto microscope slides using DAPI Fluoromount-G (Southern Biotech #0100–20) and coverslipped before confocal imaging.
Following all behavioral experiments, mice were anesthetized with an intraperitoneal injection of Ketamine-Xylazine (120mg/kg Ketamine, 24 mg/kg Xylazine) and transcardially perfused with PBS followed by 10% neutral-buffered formalin. The brain was delicately extricated and stored in 10% neutral-buffered formalin overnight at 4°C. Tissue was mounted onto a stage and sectioned at 100μm using a VT-1000 vibratome (Leica). Sections were mounted and coverslipped using DAPI Fluoromount-G (Southern Biotech #0100–20). Confocal images were acquired using a LSM800 confocal laser scanning microscope (Zeiss) for injection site location verification, cannula placement, and viral expression in POm axons within pDLS and stereotypical POm-cortical projections in S1 L1 and L5a of all experimental mice.4 (link),25 (link),26 (link),47 (link),49 (link) All data were acquired using the Zen software suite (Zeiss).