Fig. 7.
MOR-labeled axon terminals sometimes contact NK1-immunoreactive dendrites. An immunoperoxidase-labeled axon terminal (MOR-t) forms a symmetric synapse (filled curved arrow) with an immunogold-labeled dendrite (NK1-d). The MOR labeling is strongly associated with dense-core vesicles (dcv). The dendrite is also apposed to a MOR-labeled axon (MOR-a) at the head of a small spine (open arrow). Most of the immunogold particles (arrowheads) are associated with nonsynaptic portions of the plasma membrane. Scale bar, 0.5 μm.