Role of the spinal Na+/H+ exchanger in formalin-induced nociception

► Spinal administration of NHE inhibitors increased formalin-induced nociception. ► NHE1 like-immunoreactivity was found in lamina I and lamina II of the lumbar spinal cord. ► NHE1 colocalized with CGRP and SP. ► NHE1 plays an antinociceptive role at spinal level.