Immunofluorescence Labeling of Mouse Spinal Cord

The procedures were described previously^{37 (link),62} . Deeply anesthetized mice (ketamine, 90 mg/kg and Xylazine, 10 mg/kg) were perfused transcardially with 0.01 M PBS (PH 7.4) and paraformaldehyde (PFA) (4% in PBS). Spinal cord and brain were removed and post-fixed in 4% PFA for 2–4 h. The tissues were then cryoprotected in 20% sucrose overnight at 4 °C. Free-floating frozen sections were incubated with 2% donkey serum and 0.3% Triton X-100 for 1 h at room temperature followed by incubation with primary antibodies overnight at 4 °C. The sections were then washed and incubated with secondary antibodies for 2 h at room temperature. The following primary antibodies were used: chicken anti-GFP (1:500, Aves Labs, GFP-1020), guinea-pig anti-NK1R (1:500, AB15810, EMD Millipore), rabbit anti-FG (1:5000, AB153, Millipore). The following secondary antibodies were used: Alexa-Fluor 488 conjugated donkey anti-chicken (1:1000, Jackson ImmunoResearch, 703–545–155), Cy3-conjugated donkey anti-rabbit (1:1000, Jackson ImmunoResearch, 711–165–152) and Cy5-conjugated donkey anti-guinea pig 1(:1000, Jackson ImmunoResearch, 703–175–148). Fluorescent Images were taken using a Nikon C2+ confocal microscope system (Nikon Instruments, Inc.).