title: Vasopressin casts light on the suprachiasmatic nucleus.
abstract: A subpopulation of retinal ganglion cells expresses the neuropeptide vasopressin. These retinal ganglion cells project predominately to our biological clock, the suprachiasmatic nucleus (SCN). Light-induced vasopressin release enhances the responses of SCN neurons to light. It also enhances expression of genes involved in photo-entrainment of biological rhythms.
  
  
  
  In all animals, the transition between night and day engages a host of physiological and behavioural rhythms. These rhythms depend not on the rods and cones of the retina, but on retinal ganglion cells (RGCs) that detect the ambient light level in the environment. These project to the suprachiasmatic nucleus (SCN) of the hypothalamus to entrain circadian rhythms that are generated within the SCN. The neuropeptide vasopressin has an important role in this entrainment. Many SCN neurons express vasopressin, and it has been assumed that the role of vasopressin in the SCN reflects the activity of these cells. Here we show that vasopressin is also expressed in many retinal cells that project to the SCN. Light-evoked vasopressin release contributes to the responses of SCN neurons to light, and enhances expression of the immediate early gene c-fos in the SCN, which is involved in photic entrainment of circadian rhythms.
authors.affiliation: Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tsuji
authors.affiliation: Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Allchorne
authors.affiliation: Department of Physiology, Augusta University, Augusta, GA, USA.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.
authors.forename: Chiharu
authors.initials: C
authors.lastname: Tsuji
authors.affiliation: Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.
authors.forename: Vicky A
authors.initials: VA
authors.lastname: Tobin
authors.affiliation: Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.
authors.forename: Rafael
authors.initials: R
authors.lastname: Pineda
authors.affiliation: Schaller Research Group on Neuropeptides, German Cancer Research Centre DKFZ, Central Institute of Mental Health, and University of Heidelberg, Heidelberg, Germany.
authors.forename: Androniki
authors.initials: A
authors.lastname: Raftogianni
authors.affiliation: Department of Physiology, Augusta University, Augusta, GA, USA.
authors.forename: Javier E
authors.identifier: 0000-0002-9310-0486
authors.initials: JE
authors.lastname: Stern
authors.affiliation: Schaller Research Group on Neuropeptides, German Cancer Research Centre DKFZ, Central Institute of Mental Health, and University of Heidelberg, Heidelberg, Germany.
authors.forename: Valery
authors.initials: V
authors.lastname: Grinevich
authors.affiliation: Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.
authors.forename: Gareth
authors.initials: G
authors.lastname: Leng
authors.affiliation: Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.
authors.forename: Mike
authors.identifier: 0000-0001-9983-4950
authors.initials: M
authors.lastname: Ludwig
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D005260:Female; D008027:Light; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012165:Retinal Ganglion Cells / Q000378:metabolism* / Q000502:physiology / Q000528:radiation effects; D013493:Suprachiasmatic Nucleus / Q000378:metabolism* / Q000502:physiology; D014667:Vasopressins / Q000378:metabolism*
chemical_list: D014667:Vasopressins
keywords: electrophysiology; microdialysis; retinal ganglion cells; suprachiasmatic nucleus; vasopressin