title: Expression of the c-fos-monomeric red fluorescent protein 1 fusion gene in the spinal cord and the hypothalamic paraventricular nucleus in transgenic rats after nociceptive stimulation.
abstract: We generated transgenic rats expressing the c-fos and monomeric red fluorescent protein 1 (mRFP1) fusion gene in the central nervous system after adequate stimulation. In the present study, the time-course of the induction patterns of mRFP1 fluorescence in the spinal cord and the paraventricular nucleus (PVN) was compared with that of Fos-like immunoreactivity (LI) within 24 h after subcutaneous (s.c.) injection of 0.9% saline and 5% formalin in both hind paws. Control rats were not treated. In the control and saline/formalin injected rats, scattered mRFP1 fluorescence in the spinal cord and the PVN was observed at 0 min, though there was little Fos-LI in the same region. The mRFP1 fluorescence in the spinal cord and the PVN was increased at 3h after formalin. On the other hand, the changes of Fos-LI in the spinal cord and the PVN were relatively shorter than those of the mRFP1 fluorescence after formalin. These results suggest that the c-fos-mRFP1 fusion gene expression is slightly upregulated in normal conditions and nociceptive stimulation-induced induction of the fusion gene may be maintained longer than the endogenous c-fos gene expression in the spinal cord and the PVN. Next, nocifensive behavior and mRFP1 fluorescence and Fos-LI in the spinal cord and the PVN after s.c. injection of formalin, 4α-phorbol 12,13-didecanoate (4α-PDD) and saline were compared. Although the 4α-PDD injected rats seldom displayed nocifensive behaviors like s.c. saline injection, 4α-PDD injection caused mRFP1 fluorescence and Fos-LI significantly in the spinal cord and the PVN unlike s.c. saline injection.
authors.affiliation: Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu 807-8555, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Ishikura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Suzuki
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Yoshimura
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Ohkubo
authors.forename: Akiko
authors.initials: A
authors.lastname: Katoh
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Ohbuchi
authors.forename: Motoko
authors.initials: M
authors.lastname: Ohno
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Fujihara
authors.forename: Makoto
authors.initials: M
authors.lastname: Kawasaki
authors.forename: Hideo
authors.initials: H
authors.lastname: Ohnishi
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Nakamura
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Ueta
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation; D050939:Gene Fusion; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics*; D008297:Male; D010147:Pain Measurement / Q000379:methods*; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis / Q000235:genetics*; D051381:Rats; D055647:Rats, Transgenic; D017208:Rats, Wistar; D013116:Spinal Cord / Q000378:metabolism*; D000097573:Red Fluorescent Protein
chemical_list: D008164:Luminescent Proteins; D016760:Proto-Oncogene Proteins c-fos; D000097573:Red Fluorescent Protein