Fig. 1: Identification of midbrain/medulla-projecting neurons in the sensorimotor cortex.

a Sagittal schematic showing the strategy to label cortical projection terminals. b and c Brain sections of virus injection site and projection terminals in PAG and RVM of S1 (b) and M1 (c). Scale bars, 200 μm. Both experiments were independently repeated three times from three mice with similar results. d Schematic showing the dual retro-virus labeling strategy. e Localization of retro-virus labeled neurons in sensorimotor cortex. Green and Red dots represent labeled SM1^PAG and SM1^RVM neurons. f Relative proportion of labeled cells within S1, M1, and M2. g Cell density of SM1^PAG and SM1^RVM throughout the AP extent of SM1. h SM1 sections showing SM1 subpopulations localization. Scale bars, 100 μm. This experiment was independently repeated four times from four mice with similar results. i Sections showing the distribution (left) and relative proportion (right) of labeled cells in layer structure of SM1. Scale bars, 100 μm. j Schematic showing the proportion of labeled PAG- and RVM-projecting neurons in SM1. k and l RNAscope FISH showing colocalization and proportion of vGlut1 or vGat mRNA with SM1^PAG (k) and SM1^RVM (l) in the SM1. Scale bars, 100 μm. All data are expressed as mean ± sem. Source data are provided as a Source Data file.