(A, D) Multiplex in situ hybridization indicates that Ighg3 (blue) expression occurs only in a subset of Gad67+ inhibitory interneurons (green) (A, D). (B, C, D) Multiplex in situ hybridization using probes against Ighm (blue), vGAT (green) (B), and vGluT2 (green) (C) demonstrates expression of Ighm in excitatory and inhibitory spinal neurons (B, C, D). (D) Quantification of the number of Ighg3/Ighm–positive cells that also express the indicated marker. Error bars: SD. Sale bar: 20 μm.