Fig. 2
From: Itch suppression in mice and dogs by modulation of spinal α2 and α3GABAA receptors
α2 and α3GABAARs are expressed on key elements of a spinal itch relay circuit. Expression of GABAAR α subunits in MrgprA3 positive primary pruritoceptors (a, b) and GRP positive dorsal horn neurons (c, d). a–d show transverse sections of the lumbar spinal cord of two MrgprA3::cre;ROSA26lsl-tdTom and three GRP::eGFP transgenic mice stained with antibodies against α1, α2, α3, and α5GABAAR subunits. td-Tom and eGFP are shown in green, GABAAR α subunits in red. Overlapping expression (light green/yellow) of GABAAR α subunits with tdTom and eGFP was seen for α2 and α3GABAAR subunits, but not for α1 and α5GABAAR subunits. b, d Confocal analyses. Orthogonal views (stacks of 17–35 sections (1024 × 1024 pixels) at 0.4 µm intervals) verify co-localization of α2 and α3GABAAR subunits with MrgprA3 positive fibers and terminals (b) and GRP positive dorsal horn neurons (e) at higher magnification. Arrowheads indicate examples of co-localization. Scales bars, 50 µm (a, c), 5 µm (b, d). e Fluorescent in situ hybridization signals of α2 (red) and α3 (blue) subunits together with eGFP (to detect MrgprA3 neurons DRG neurons in MrgprA3::cre-eGFP transgenic mice), GRP and GRPR in situ hybridization signals (green, in wild-type mice). DAPI staining (gray) was used to indicate the location of cells. Bar charts: percent GABAAR α subunit positive neurons among the marker (MrgprA3, GRP, and GRPR) positive neurons. Each data point represents one mouse. Sections were obtained from 3–5 mice. Scale bar, 20 µm
