Fig. 2.
The IP receptor is expressed in lumbar dorsal horn neurons. (A) Immunohistochemical staining showing IP receptor and the peptidergic C-fiber marker calcitonin gene-related peptide (CGRP) in incoming peripheral nociceptive fibers as well as in dorsal horn neurons. (B) No colocalization of isolectin B4 (IB4), a marker for nonpeptidergic C-fibers, with IP-positive neurons or fibers. (C) IP receptor costaining with the neuron marker NeuN. (D) IP-expressing neurons are surrounded by prostacyclin synthase (PGIS) expressing cells in the dorsal horn. Scale bar represents 100 µm. The insets are magnifications of the areas shown as white boxes.