Melanopsin Is Required for Non-Image-Forming Photic Responses in Blind Mice

  title={Melanopsin Is Required for Non-Image-Forming Photic Responses in Blind Mice},
  author={Satchidananda Panda and Ignacio Provencio and Daniel C. Tu and Susana Salgado Pires and Mark D. Rollag and Ana Maria Castrucci and Mathew T. Pletcher and Trey K. Sato and Tim Wiltshire and Mary Andahazy and Steve A. Kay and Russell N. Van Gelder and John B. Hogenesch},
  pages={525 - 527}
Although mice lacking rod and cone photoreceptors are blind, they retain many eye-mediated responses to light, possibly through photosensitive retinal ganglion cells. These cells express melanopsin, a photopigment that confers this photosensitivity. Mice lacking melanopsin still retain nonvisual photoreception, suggesting that rods and cones could operate in this capacity. We observed that mice with both outer-retinal degeneration and a deficiency in melanopsin exhibited complete loss of… 

Residual photosensitivity in mice lacking both rod opsin and cone photoreceptor cyclic nucleotide gated channel 3 α subunit

It seems that non-rod non-cone photoreceptors can drive many, but not all, non-image-forming light responses, including photoentrainment of the circadian clock and the pupil light reflex.

Melanopsin and Mechanisms of Non-visual Ocular Photoreception*

In addition to rods and cones, the mammalian eye contains a third class of photoreceptor, the intrinsically photosensitive retinal ganglion cell (ipRGC). ipRGCs are heterogeneous irradiance-encoding

Visual Responses in Mice Lacking Critical Components of All Known Retinal Phototransduction Cascades

The data suggest that a Gnat1-independent phototransduction mechanism downstream of rod opsin can support relatively widespread responses in the mammalian visual system.

Melanopsin-Dependent Non-Visual Responses by Light : Evidence for Photopigment Bistability in vivo

It is found that pre-stimulation with long wavelength light not only restores but enhances single unit responses of SCN neurons to 480 nm light, whereas the long-wavelength stimulus alone fails to elicit any response.

Intrinsically photosensitive retinal ganglion cells detect light with a vitamin A-based photopigment, melanopsin.

  • Yingbin FuH. Zhong K. Yau
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 2005
Study of mice lacking RPE65, a protein essential for the regeneration of rod and cone pigments, and exogenous all-trans-retinal was also able to rescue the low sensitivity of rpe65-/- ipRGCs suggest melanopsin could be a bistable pigment.

Multiple photoreceptors contribute to nonimage-forming visual functions predominantly through melanopsin-containing retinal ganglion cells.

Under conditions where melanopsin-containing retinal ganglion cells were genetically ablated, image formation is maintained, whereas circadian photoentrainment and pupillary light reflex are severely impaired.

Melanopsin phototransduction: slowly emerging from the dark.




Diminished Pupillary Light Reflex at High Irradiances in Melanopsin-Knockout Mice

It is reported that in mice with the melanopsin gene ablated, RGCs retrograde-labeled from the suprachiasmatic nuclei were no longer intrinsically photosensitive, although their number, morphology, and projections were unchanged.

Characterization of an ocular photopigment capable of driving pupillary constriction in mice

This work demonstrates that transgenic mice lacking both rod and cone photoreceptors (rd/rd cl) retain a pupillary light reflex (PLR) that does not rely on local iris photoreCEPTors, and represents the first functional characterization of a non-rod, non-cone photoreceptive system in the mammalian CNS.

Melanopsin-Containing Retinal Ganglion Cells: Architecture, Projections, and Intrinsic Photosensitivity

It is shown that melanopsin is present in cell bodies, dendrites, and proximal axonal segments of a subset of rat RGCs, most likely the visual pigment of phototransducing R GCs that set the circadian clock and initiate other non–image-forming visual functions.

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

These mice display severely attenuated phase resetting in response to brief pulses of monochromatic light, highlighting the critical role of melanopsin in circadian photoentrainment in mammals.

Phototransduction by Retinal Ganglion Cells That Set the Circadian Clock

It is shown that retinal ganglion cells innervating the SCN are intrinsically photosensitive, and depolarized in response to light even when all synaptic input from rods and cones was blocked.

Role of Melanopsin in Circadian Responses to Light

Although melanopsin is not essential for the circadian clock to receive photic input, it contributes significantly to the magnitude of photic responses.

Vitamin B2-based blue-light photoreceptors in the retinohypothalamic tract as the photoactive pigments for setting the circadian clock in mammals.

  • Y. MiyamotoA. Sancar
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1998
It is proposed that mammals have a vitamin A-based photopigment for vision and a vitamin B2-based pigment (cryptochrome) for entrainment of the circadian clock.

Circadian photoreception in the retinally degenerate mouse (rd/rd)

No photoreceptor outersegments were identified in the retina of rd/rd animals (80–100 days of age), but a small number of perikarya that were immunoreactive for cone opsins, and even fewer cells that contained rod opsin were identified.

Reduced Pupillary Light Responses in Mice Lacking Cryptochromes

Mice with severe degeneration of the outer retina still retain substantial photic sensitivity for pupillary responses ([1][1], [2][2]), as well as for other light-regulated phenomena including phase

Melanopsin retinal ganglion cells receive bipolar and amacrine cell synapses

Observations suggested that rod and/or cone signals may be capable of modifying the intrinsic light response in melanopsin‐expressing retinal ganglion cells.