| First Author | Rau KK | Year | 2009 |
| Journal | J Neurosci | Volume | 29 |
| Issue | 26 | Pages | 8612-9 |
| PubMed ID | 19571152 | Mgi Jnum | J:150802 |
| Mgi Id | MGI:3851846 | Doi | 10.1523/JNEUROSCI.1057-09.2009 |
| Citation | Rau KK, et al. (2009) Mrgprd enhances excitability in specific populations of cutaneous murine polymodal nociceptors. J Neurosci 29(26):8612-9 |
| abstractText | The Mas-related G protein-coupled receptor D (Mrgprd) is selectively expressed in nonpeptidergic nociceptors that innervate the outer layers of mammalian skin. The function of Mrgprd in nociceptive neurons and the physiologically relevant somatosensory stimuli that activate Mrgprd-expressing (Mrgprd(+)) neurons are currently unknown. To address these issues, we studied three Mrgprd knock-in mouse lines using an ex vivo somatosensory preparation to examine the role of the Mrgprd receptor and Mrgprd(+) afferents in cutaneous somatosensation. In mouse hairy skin, Mrgprd, as marked by expression of green fluorescent protein reporters, was expressed predominantly in the population of nonpeptidergic, TRPV1-negative, C-polymodal nociceptors. In mice lacking Mrgprd, this population of nociceptors exhibited decreased sensitivity to cold, heat, and mechanical stimuli. Additionally, in vitro patch-clamp studies were performed on cultured dorsal root ganglion neurons from Mrgprd(-/-) and Mrgprd(+/-) mice. These studies revealed a higher rheobase in neurons from Mrgprd(-/-) mice than from Mrgprd(+/-) mice. Furthermore, the application of the Mrgprd ligand beta-alanine significantly reduced the rheobase and increased the firing rate in neurons from Mrgprd(+/-) mice but was without effect in neurons from Mrgprd(-/-) mice. Our results demonstrate that Mrgprd influences the excitability of polymodal nonpeptidergic nociceptors to mechanical and thermal stimuli. |
