Melanopsin (Opn4) Requirement for Normal Light-Induced Circadian Phase Shifting

  title={Melanopsin (Opn4) Requirement for Normal Light-Induced Circadian Phase Shifting},
  author={Satchidananda Panda and Trey K. Sato and Ana Maria Castrucci and Mark D. Rollag and Willem J. DeGrip and John B. Hogenesch and Ignacio Provencio and Steve A. Kay},
  pages={2213 - 2216}
The master circadian oscillator in the hypothalamic suprachiasmatic nucleus is entrained to the day/night cycle by retinal photoreceptors. Melanopsin (Opn4), an opsin-based photopigment, is a primary candidate for photoreceptor-mediated entrainment. To investigate the functional role of melanopsin in light resetting of the oscillator, we generated melanopsin-null mice (Opn4 −/−). These mice entrain to a light/dark cycle and do not exhibit any overt defect in circadian activity rhythms under… 

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