Distribution of α4β2 nicotinic acetylcholine receptors in neuronal populations of mouse spinal dorsal horn

To elucidate the roles of α4β2 nicotinic acetylcholine receptors (nAChRs) in nociceptive somatosensory processing, we examined the localization and expression of α4β2 nAChR subunits in neurons of the superficial spinal dorsal horn (SDH) in mice. Among the nAChR subunits, α4 (Chrna4) and β2 (Chrnb2) exhibited the highest mRNA expression levels in the SDH. In Chrna4–enhanced green fluorescent protein (EGFP) mice, EGFP reflecting α4 subunit expression was abundantly detected in both excitatory and inhibitory SDH neurons. Further functional validation of α4β2 nAChRs expressed across distinct neuronal populations may clarify their novel roles in the regulation of pain and itch processing.