Figure 3.
Electron microscopic visualization evidence for U50,488-induced internalization of κOR in locus coeruleus (LC) dendrites. Sections from control (vehicle-treated) (A), U50,488-treated (B) and norBNI-pretreated rats prior to U50488 treatment (C). A. Immunogold-silver labeling for κOR (arrows) can be seen along the plasmalemma in a dendrite from vehicle-treated rats. A κOR-labeled dendrite receives synaptic contacts from an axon terminal (t). B. κOR labeling shifts from the plasmalemma (arrow) to the cytoplasm (arrowheads) in a dendrite following U50,488 treatment. Arrowheads point to immunogold-silver labeling in the cytoplasm. C. Immunogold-silver labeling for κOR can be seen along the plasmalemma (arrow) and also in the cytoplasm (arrowhead) in a dendritic profile following norBNI treatment prior to U50488 injection. Scale bars, 0.5μm.