title: Involvement of GluR2 and GluR3 subunit C-termini in the trigeminal spinal subnucleus caudalis and C1-C2 neurons in trigeminal neuropathic pain.
abstract: To clarify the involvement of GluR2 and GluR3 subunits of AMPA receptor in orofacial neuropathic pain, we studied changes in nocifensive behavior and extracellular-signal regulated kinase (ERK) phosphorylation followed by infraorbital nerve (ION)-partial transection model applied to GluR2 or GluR3 delta7 knock-in (KI) mice. In these animals, last seven amino acids of GluR2 or GluR3 subunit, the binding sites of interacting protein, are deleted in vivo. Head-withdrawal threshold to mechanical stimulation of the whisker pad skin ipsilateral to ION-partial transection was significantly reduced at 1, 3, 5, 7, 11 and 14 days after transection compared with that before transection in wild-type mice. In the GluR2 and GluR3 delta7 KI mice, the head-withdrawal threshold did not change following ION-partial transection. The number of pERK-LI cells examined in Vc and C1-C2 in wild-type mice after the non-noxious stimulation was larger than that of GluR2 and GluR3 delta7 KI mice. The present findings suggest that GluR2 and GluR3 subunits of AMPA receptor play roles in the trigeminal nerve injury-mediated enhancement of Vc and C1-C2 neuronal excitability, and hyperalgesia.
authors.affiliation: Department of Anesthesiology, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Makiko
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Tsuboi
authors.forename: Kogo
authors.initials: K
authors.lastname: Takamiya
authors.forename: Richard L
authors.initials: RL
authors.lastname: Huganir
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kondo
authors.forename: Masamichi
authors.initials: M
authors.lastname: Shinoda
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Oi
authors.forename: Koichi
authors.initials: K
authors.lastname: Iwata
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D055879:Gene Knock-In Techniques; D006930:Hyperalgesia / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009619:Nociceptors / Q000473:pathology / Q000502:physiology*; D010446:Peptide Fragments / Q000235:genetics / Q000502:physiology; D020671:Posterior Horn Cells / Q000473:pathology / Q000502:physiology*; D021122:Protein Subunits / Q000235:genetics / Q000502:physiology*; D018091:Receptors, AMPA / Q000235:genetics / Q000502:physiology*; D014275:Trigeminal Caudal Nucleus / Q000473:pathology / Q000502:physiology*; D014277:Trigeminal Neuralgia / Q000378:metabolism* / Q000473:pathology
chemical_list: D010446:Peptide Fragments; D021122:Protein Subunits; D018091:Receptors, AMPA; C104723:glutamate receptor ionotropic, AMPA 3; C104722:glutamate receptor ionotropic, AMPA 2