Schematic representation of TAAR4a,4b expression and amine responses.
The top panel shows a horizontal section of the MOE of Xenopus laevis as it appears both for measuring odor responses and receptor gene expression. The basalmost layer of the epithelium borders the basal lamina and the apicalmost layer borders the lumen. The apicalmost layer consists of supporting cells and the basalmost region of proliferating cells, sandwiching the neuronal region. Perpendicular to this basal-to-apical coordinate, cells in the MOE can also be distinguished by position in the lateral, intermediate, or medial compartment (lateral-to-medial coordinate). The bottom panel depicts a schematic representation of the different cellular distributions analysed. Note that only the neuronal region of the MOE is shown here. Distributions are shown along two axes, basal-to-apical and lateral-to-medial. OMP and TRPC2 distributions are taken from earlier work of our groups2,4 and are shown for comparison. We emphasize that TAAR4a and TAAR4b differ in both dimensions and together comprise a large subset of the bimodal amine response region.