Figure 6.
μ opioid receptors are expressed by primary afferent C and Aδ nerve fibers and some microglia. (a) Confocal images of μ opioid receptor (green) and CD11b (red) immunofluorescence colocalization in microglial processes (arrows). (b) Confocal images of μ opioid receptor (green) and CD11b (red) immunofluorescence colocalization in microglial cell bodies (arrow heads). (c) Immunofluorescence images of μ opioid receptor (red) and CGRP (green) colocalization in afferent presynaptic nerve terminals (arrows). (d) Immunofluorescence images of μ opioid receptor (red) and NeuN (green) with no colocalization (open arrow heads). Scale bars equal 10 μm.