In order for humans to see infrared, the spectral sensitivity of some human photopigment would have to be changed.    From Wordnik.com.  [Mind Hacks: August 2005 Archives] Reference

Vision scientists knew that retinal, the derivative of vitamin A, was part of every photopigment molecule and that various forms of vitamin A existed.    From Wordnik.com.  [Mind Hacks: August 2005 Archives] Reference

For example, he would claim that a photopigment without any linkers or down stream signalling molecules would be useless, and unselectable by natural selection.    From Wordnik.com.  [Blind Mice vs Behe; the Evolution of Vision - The Panda's Thumb] Reference

The ability to see the world as humans do, he says, ‘requires an additional sensor—or photopigment—and the nervous system being able to compare the signals.’.    From Wordnik.com.  [Three Color Blind Mice: See How They See : Edward Champion’s Reluctant Habits] Reference

Invertebrates have rhabodomeric cells that use a special version of the photopigment called r-opsin, and activate cells by a particular pathway called a phospholipase-C cascade.    From Wordnik.com.  [PZ Myers - The Deepest Links (on Evolution)] Reference

This prompted mammalian researchers to check if cryptochrome also acts as a photopigment in mammals.    From Wordnik.com.  [ScienceBlogs Channel : Life Science] Reference

Melanopsin is a photopigment that helps regulate circadian rhythms and other non-visual responses in the eye.    From Wordnik.com.  [Genetics & Health] Reference

Douglas RH, Foster RG (2001) Characterization of an ocular photopigment capable of driving pupillary constriction in mice.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

Magnetosensitivity is maximal at the absorbance maximum of the photopigment, and it depends on the strength of the magnetic field.    From Wordnik.com.  [PLoS Biology: New Articles] Reference

So far our results are consistent with the idea that magnetoreception involves a radical-pair mechanism occurring in a photopigment.    From Wordnik.com.  [PLoS Biology: New Articles] Reference

Callonychium petuniae has a 4th spectral class of receptor, which appears to be based on a photopigment with a peak sensitivity of about 600 nm.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

Since the radical-pair mechanism of magnetosensitivity depends on the activation of the relevant photopigment by light, it is wavelength dependent.    From Wordnik.com.  [PLoS Biology: New Articles] Reference

Birds that can do magnetic compass orientation also depend on light, and the blue-light photopigment cryptochrome was proposed to act as a navigational magnetosensor.    From Wordnik.com.  [PLoS Biology: New Articles] Reference

Provencio and his colleagues have discovered that melanopsin, a photopigment gene in the eye, may play a role in causing SAD in people with a recently discovered mutation.    From Wordnik.com.  [innovations-report] Reference

The theoretical basis of most attempts to derive universal photopigment spectral sensitivity templates is that the form of the resulting curve is shape invariant when plotted on the.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

Further analysis showed that retinal photoreceptor cells in the mouse model were most likely dying as a result of a toxic accumulation of the very photopigment, which receives light signals in the eye and is crucial for normal vision.    From Wordnik.com.  [Gaea Times (by Simple Thoughts) Breaking News and incisive views 24/7] Reference

Further investigation revealed that retinal photoreceptor cells in the mouse model were most likely dying as a result of a toxic accumulation of the very photopigment that receives light signals in the eye and is crucial for normal vision.    From Wordnik.com.  [Science Blog] Reference

The electrical signal generated by a photoreceptor depends primarily on its photopigment, but clearly there can be many other interacting factors, especially in the in situ recordings used here, where the optics of the eye are essentially intact.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

Japan The photopigment melanopsin has been suggested to act as a dominant photoreceptor in nonvisual photoreception including resetting of the circadian clock (entrainment), direct tuning or masking of vital status (activity, sleep/wake cycles, etc.), and the pupillary light reflex.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

The photopigment melanopsin has been suggested to act as a dominant photoreceptor in nonvisual photoreception including resetting of the circadian clock (entrainment), direct tuning or masking of vital status (activity, sleep/wake cycles, etc.), and the pupillary light reflex (PLR).    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

Non-image related responses to light, such as the synchronization of circadian rhythms to the day / night cycle, are mediated by classical rod / cone photoreceptors and by a small subset of retinal ganglion cells that are intrinsically photosensitive, expressing the photopigment, melanopsin.    From Wordnik.com.  [ScienceBlogs Channel : Life Science] Reference

As discussed above, electrophysiological measurements may only indirectly reflect underlying photopigment absorbance spectra, but we also note that there can be deviations from predicted spectra even when based on isolated photoreceptor photocurrents: for example recordings from amphibian cones have revealed narrower than predicted spectra.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

These 'nonvisual' light responses have been suggested to be predominantly mediated by the novel photopigment melanopsin Pituitary adenylate cyclase-activating polypeptide (PACAP) belongs to the vasoactive intestinal polypeptide (VIP)/glucagons/secretin family and plays pleiotropic roles as a neurotransmitter, neuromodulator and neurotrophic factor.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

In actual fact the visual transduction system isn’t terribly complicated at all; there is a photopigment opsin, an adaptor protein, an enzyme, and a target protein.    From Wordnik.com.  [Blind Mice vs Behe; the Evolution of Vision - The Panda's Thumb] Reference

(2002) The photopigment melanopsin is exclusively present in pituitary adenylate cyclase-activating polypeptide-containing retinal ganglion cells of the retinohypothalamic tract.    From Wordnik.com.  [PLoS ONE Alerts: New Articles] Reference

1) group of different conditions all marked by rod and cone dystrophy 2) most common causes are mutations in genes for peripherin, rhodopsin, and rod photopigment.    From Wordnik.com.  [InsideSurgery Medical Information Blog] Reference