Fig. 8.

KORs are primarily localized presynaptically in embryonic spinal neurons. A, a large proportion of KORs are colocalized with VGlut2 in spinal neurons, demonstrating the localization of KORs in glutamatergic neurons. a, confocal images show phase, VGlut2 (red), and KOR (green) immunolabeling separately with regions of colocalization that appear as yellow puncta (scale bar, 10 μm). b, boxed region shown in higher magnification (scale bar, 5 μm) separately and overlaid. B, subcellular fractionation of embryonic spinal neurons in culture shows the relative abundance of KORs in the crude synaptic vesicle fraction (LP2 fraction). Data are from a representative experiment performed.