Calca mRNA labeling identifies a subpopulation of parabrachial nucleus (PB) glutamatergic neurons. In this example, centered over the external lateral subnucleus (PBeL), (a) Calca mRNA (red) uniformly co-localized with (b) Slc17a6 mRNA (Vglut2, green), and (c) Ubc mRNA (ubiquitin, blue, shown for neuroanatomical background), with the combination of all three genes shown in panel (d). Scale bar in panel (a) is 100 μm and applies to all panels.