title: Possible Involvement of the Rat Hypothalamo-Neurohypophysial/-Spinal Oxytocinergic Pathways in Acute Nociceptive Responses.
abstract: Oxytocin (OXT)-containing neurosecretory cells in the parvocellular divisions of the paraventricular nucleus (PVN), which project to the medulla and spinal cord, are involved in various physiological functions, such as sensory modulation and autonomic processes. In the present study, we examined OXT expression in the hypothalamo-spinal pathway, as well as the hypothalamo-neurohypophysial system, which includes the magnocellular neurosecretory cells in the PVN and the supraoptic nucleus (SON), after s.c. injection of saline or formalin into the hindpaws of transgenic rats that express the OXT and monomeric red fluorescent protein 1 (mRFP1) fusion gene. (i) The numbers of OXT-mRFP1 neurones that expressed Fos-like immunoreactivity (-IR) and OXT-mRFP1 intensity were increased significantly in the magnocellular/parvocellular PVN and SON after s.c. injection of formalin. (ii) OXT-mRFP1 neurones in the anterior parvocellular PVN, which may project to the dorsal horn of the spinal cord, were activated by s.c. injection of formalin, as indicated by a significant increases of Fos-IR and mRFP1 intensity intensity. (iii) Formalin injection caused a significant transient increase in plasma OXT. (iv) OXT, mRFP1 and corticotrophin-releasing hormone mRNAs in the PVN were significantly increased after s.c. injection of formalin. (v) An intrathecal injection of OXT-saporin induced hypersensitivity in conscious rats. Taken together, these results suggest that the hypothalamo-neurohypophysial/-spinal OXTergic pathways may be involved in acute nociceptive responses in rats.
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.|Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Matsuura
authors.affiliation: Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kawasaki
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Hashimoto
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yoshimura
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.|Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Motojima
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: R
authors.initials: R
authors.lastname: Saito
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ueno
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Maruyama
authors.affiliation: Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ishikura
authors.affiliation: Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Sabanai
authors.affiliation: Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mori
authors.affiliation: Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ohnishi
authors.affiliation: Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University, Shimotsuke-shi, Tochigi-ken, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Onaka
authors.affiliation: Department of Orthopaedics, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Sakai
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ueta
mesh_terms: D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000096:biosynthesis; D005557:Formaldehyde; D006930:Hyperalgesia / Q000139:chemically induced* / Q000503:physiopathology*; D007031:Hypothalamus / Q000378:metabolism*; D007278:Injections, Spinal; D008164:Luminescent Proteins / Q000235:genetics; D008297:Male; D009474:Neurons / Q000378:metabolism; D010121:Oxytocin / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000097:blood / Q000494:pharmacology / Q000502:physiology*; D010147:Pain Measurement; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism / Q000502:physiology; D010904:Pituitary Gland, Posterior / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D055647:Rats, Transgenic; D054789:Ribosome Inactivating Proteins, Type 1 / Q000008:administration & dosage / Q000494:pharmacology; D000076985:Saporins; D013495:Supraoptic Nucleus / Q000378:metabolism / Q000502:physiology; D000097573:Red Fluorescent Protein
chemical_list: D003346:Corticotropin-Releasing Hormone; D005557:Formaldehyde; D008164:Luminescent Proteins; D010121:Oxytocin; D016760:Proto-Oncogene Proteins c-fos; D054789:Ribosome Inactivating Proteins, Type 1; D000076985:Saporins; D000097573:Red Fluorescent Protein; C000620614:oxytocin-saporin
keywords: acute nociception; fluorescent protein; oxytocin