Circadian rhythm of contrast sensitivity is regulated by a dopamine-neuronal PAS-domain protein 2-adenylyl cyclase 1 signaling pathway in retinal ganglion cells

J Neurosci. 2013 Sep 18;33(38):14989-97. doi: 10.1523/JNEUROSCI.2039-13.2013.


Spatial variation in light intensity, called spatial contrast, comprises much of the visual information perceived by mammals, and the relative ability to detect contrast is referred to as contrast sensitivity (Purves et al., 2012). Recently, retinal dopamine D4 receptors (D4Rs) have been implicated in modulating contrast sensitivity (Jackson et al., 2012); however, the cellular and molecular mechanisms have not been elucidated. Our study demonstrates a circadian rhythm of contrast sensitivity that peaks during the daytime, and that its regulation involves interactions of D4Rs, the clock gene Npas2, and the clock-controlled gene adenylyl cyclase 1 (Adcy1) in a subset of retinal ganglion cells (RGCs). Targeted disruption of the gene encoding D4Rs reduces the amplitude of the contrast sensitivity rhythm by reducing daytime sensitivity and abolishes the rhythmic expression of Npas2 and Adcy1 mRNA in the ganglion cell layer (GCL) of the retina. Npas2(-/-) and Adcy1(-/-) mice show strikingly similar reductions in the contrast sensitivity rhythm to that in mice lacking D4Rs. Moreover, Adcy1 transcript rhythms were abolished in the GCL of Npas2(-/-) mice. Luciferase reporter assays demonstrated that the Adcy1 promoter is selectively activated by neuronal PAS-domain protein 2 (NPAS2)/BMAL1. Our results indicate that the contrast sensitivity rhythm is modulated by D4Rs via a signaling pathway that involves NPAS2-mediated circadian regulation of Adcy1. Hence, we have identified a circadian clock mechanism in a subset of RGCs that modulates an important aspect of retinal physiology and visual processing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ARNTL Transcription Factors / metabolism
  • Adenylyl Cyclases / deficiency
  • Adenylyl Cyclases / genetics
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors / genetics
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Cell Line, Transformed
  • Circadian Rhythm / genetics
  • Circadian Rhythm / physiology*
  • Contrast Sensitivity / genetics
  • Contrast Sensitivity / physiology*
  • Dopamine / metabolism*
  • Gene Expression Regulation / genetics
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Mutation / genetics
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Photic Stimulation
  • Receptors, Dopamine D4 / genetics
  • Receptors, Dopamine D4 / metabolism
  • Retina
  • Retinal Ganglion Cells / metabolism*
  • Signal Transduction / physiology*
  • Transfection
  • Visual Acuity
  • Visual Pathways / physiology
  • beta-Galactosidase / genetics
  • beta-Galactosidase / metabolism


  • ARNTL Transcription Factors
  • Arntl protein, mouse
  • Basic Helix-Loop-Helix Transcription Factors
  • Nerve Tissue Proteins
  • Npas2 protein, mouse
  • Receptors, Dopamine D4
  • beta-Galactosidase
  • Adenylyl Cyclases
  • adenylyl cyclase 1
  • Dopamine