Researchers find new light-sensing mechanism in neurons

Mar 03, 2011
This image shows blue-light sensing arousal neurons. Credit: UCI

A UC Irvine research team led by Todd C. Holmes has discovered a second form of phototransduction light sensing in cells that is derived from vitamin B2. This discovery may reveal new information about cellular processes controlled by light.

For more than 100 years, it had been believed that the phototransduction process was solely based on a chemical derived from vitamin A called retinal. Phototransduction is the conversion of light signals into in photoreceptive and underlies both image-forming and non-image-forming light sensing.

In discovering this new light-sensing phototransduction mechanism, the UCI scientists found that phototransduction can also be mediated by a called cryptochrome, which uses a B2 vitamin chemical derivative for light sensing. Cryptochromes are blue-light photoreceptors found in circadian and arousal neurons that regulate slow biochemical processes, but this is the first time they have been linked to rapid phototransduction.

Their work appears March 3 on online Express site for the journal Science.

"This is totally novel mechanism that does not depend on retinal," said Holmes, a professor of physiology & biophysics. "This discovery opens whole new technology opportunities for adapting light-sensing proteins to drive medically relevant cellular activities."

This basic science breakthrough – "which literally and figuratively came 'out of the blue,'" Holmes said – has implications in the fast-growing field of optogenetics. Optogenetics combines optical and genetic research techniques to probe neural circuits at the high speeds needed to understand brain information processing. In one area, it is being used to understand how treatments such as deep brain massage can aid people with neurodegenerative diseases.

Holmes' team found that cryptochrome mediates phototransduction directly in fruit fly circadian and arousal neurons in response to blue-light wavelengths. The researchers also found that they could genetically express cryptochrome in neurons that are not ordinarily electrically responsive to light to make them responsive.

Explore further: Missing protein restored in patients with muscular dystrophy

Provided by University of California - Irvine

4.8 /5 (6 votes)

Related Stories

More than meets the eye to staying awake, alert

May 13, 2010

Think twice before falling asleep alongside the glare of your computer and TV screens: exposure to dim light from ordinary room lights, computer screens and other electronic devices late at night may be interfering with our ...

Sharp-eyed robins can see magnetic fields

Jul 09, 2010

(PhysOrg.com) -- It has been known for decades that some birds are able to sense the Earth's magnetic field and set their direction as if following a compass heading, which is an extremely useful ability for ...

Recommended for you

Student seeks to improve pneumonia vaccines

17 hours ago

Almost a million Americans fall ill with pneumonia each year. Nearly half of these cases require hospitalization, and 5-7 percent are fatal. Current vaccines provide protection against some strains of the ...

Seabed solution for cold sores

18 hours ago

The blue blood of abalone, a seabed delicacy could be used to combat common cold sores and related herpes virus following breakthrough research at the University of Sydney.

Better living through mitochondrial derived vesicles

Aug 19, 2014

(Medical Xpress)—As principal transformers of bacteria, organelles, synapses, and cells, vesicles might be said to be the stuff of life. One need look no further than the rapid rise to prominence of The ...

Zebrafish help to unravel Alzheimer's disease

Aug 19, 2014

New fundamental knowledge about the regulation of stem cells in the nerve tissue of zebrafish embryos results in surprising insights into neurodegenerative disease processes in the human brain. A new study by scientists at ...

User comments : 0