title: Y-like retinal ganglion cells innervate the dorsal raphe nucleus in the Mongolian gerbil (Meriones unguiculatus).
abstract: BACKGROUND
  The dorsal raphe nucleus (DRN) of the mesencephalon is a complex multi-functional and multi-transmitter nucleus involved in a wide range of behavioral and physiological processes. The DRN receives a direct input from the retina. However little is known regarding the type of retinal ganglion cell (RGC) that innervates the DRN. We examined morphological characteristics and physiological properties of these DRN projecting ganglion cells.
  
  
  RESULTS
  The Mongolian gerbils are highly visual rodents with a diurnal/crepuscular activity rhythm. It has been widely used as experimental animals of various studies including seasonal affective disorders and depression. Young adult gerbils were used in the present study. DRN-projecting RGCs were identified following retrograde tracer injection into the DRN, characterized physiologically by extracellular recording and morphologically after intracellular filling. The result shows that DRN-projecting RGCs exhibit morphological characteristics typical of alpha RGCs and physiological response properties of Y-cells. Melanopsin was not detected in these RGCs and they show no evidence of intrinsic photosensitivity.
  
  
  CONCLUSIONS
  These findings suggest that RGCs with alpha-like morphology and Y-like physiology appear to perform a non-imaging forming function and thus may participate in the modulation of DRN activity which includes regulation of sleep and mood.
authors.affiliation: Department of Anatomy, School of Basic Medical Sciences, Peking University, Beijing, China.
authors.forename: Liju
authors.initials: L
authors.lastname: Luan
authors.forename: Chaoran
authors.initials: C
authors.lastname: Ren
authors.forename: Benson Wui-Man
authors.initials: BW
authors.lastname: Lau
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.forename: Gary E
authors.initials: GE
authors.lastname: Pickard
authors.forename: Kwok-Fai
authors.initials: KF
authors.lastname: So
authors.forename: Mingliang
authors.initials: M
authors.lastname: Pu
mesh_terms: D000818:Animals; D048430:Cell Shape / Q000528:radiation effects; D003712:Dendrites / Q000378:metabolism; D005260:Female; D005849:Gerbillinae; D042541:Intracellular Space / Q000378:metabolism / Q000528:radiation effects; D008027:Light; D011903:Raphe Nuclei / Q000166:cytology* / Q000502:physiology / Q000528:radiation effects; D012165:Retinal Ganglion Cells / Q000166:cytology* / Q000528:radiation effects; D014796:Visual Perception / Q000528:radiation effects