Retinal Innervation Tunes Circuits That Drive Nonphotic Entrainment to Food

Nature. 2020 May;581(7807):194-198. doi: 10.1038/s41586-020-2204-1. Epub 2020 Apr 22.


Daily changes in light and food availability are major time cues that influence circadian timing1. However, little is known about the circuits that integrate these time cues to drive a coherent circadian output1-3. Here we investigate whether retinal inputs modulate entrainment to nonphotic cues such as time-restricted feeding. Photic information is relayed to the suprachiasmatic nucleus (SCN)-the central circadian pacemaker-and the intergeniculate leaflet (IGL) through intrinsically photosensitive retinal ganglion cells (ipRGCs)4. We show that adult mice that lack ipRGCs from the early postnatal stages have impaired entrainment to time-restricted feeding, whereas ablation of ipRGCs at later stages had no effect. Innervation of ipRGCs at early postnatal stages influences IGL neurons that express neuropeptide Y (NPY) (hereafter, IGLNPY neurons), guiding the assembly of a functional IGLNPY-SCN circuit. Moreover, silencing IGLNPY neurons in adult mice mimicked the deficits that were induced by ablation of ipRGCs in the early postnatal stages, and acute inhibition of IGLNPY terminals in the SCN decreased food-anticipatory activity. Thus, innervation of ipRGCs in the early postnatal period tunes the IGLNPY-SCN circuit to allow entrainment to time-restricted feeding.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Axons / physiology
  • Axons / radiation effects
  • Circadian Rhythm / physiology*
  • Circadian Rhythm / radiation effects
  • Cues
  • Eating / physiology
  • Eating / radiation effects
  • Feeding Behavior / physiology*
  • Feeding Behavior / radiation effects
  • Female
  • Geniculate Bodies / cytology
  • Geniculate Bodies / physiology
  • Geniculate Bodies / radiation effects
  • Light*
  • Male
  • Mice
  • Neural Pathways* / radiation effects
  • Neuropeptide Y / metabolism
  • Retina / cytology
  • Retina / physiology*
  • Retina / radiation effects
  • Retinal Ganglion Cells / physiology
  • Retinal Ganglion Cells / radiation effects
  • Signal Transduction / radiation effects
  • Suprachiasmatic Nucleus / cytology
  • Suprachiasmatic Nucleus / physiology
  • Suprachiasmatic Nucleus / radiation effects
  • Time Factors


  • Neuropeptide Y