Navigation Links
Bright lights, not-so-big pupils
Date:12/31/2008

A team of Johns Hopkins neuroscientists has worked out how some newly discovered light sensors in the eye detect light and communicate with the brain. The report appears online this week in Nature.

These light sensors are a small number of nerve cells in the retina that contain melanopsin molecules. Unlike conventional light-sensing cells in the retinarods and conesmelanopsin-containing cells are not used for seeing images; instead, they monitor light levels to adjust the body's clock and control constriction of the pupils in the eye, among other functions.

"These melanopsin-containing cells are the only other known photoreceptor besides rods and cones in mammals, and the question is, 'How do they work?'" says Michael Do, Ph.D., a postdoctoral fellow in neuroscience at Hopkins. "We want to understand some fundamental information, like their sensitivity to light and their communication to the brain."

Using mice, the team first tested the light sensitivity of these cells by flashing light at the cells and recording the electrical current generated by one cell. They found that these cells are very insensitive to light, in contrast to rods, which are very sensitive and therefore enable us to see in dim light at night, for example. According to Do, the melanopsin-containing cells are less sensitive than cones, which are responsible for our vision in daylight.

"The next question was, What makes them so insensitive to light? Perhaps each photon they capture elicits a tiny electrical signal. Then there would have to be bright lightgiving lots of captured photonsfor a signal large enough to influence the brain. Another possibility is that these cells capture photons poorly," says Do.

To figure this out, the team flashed dim light at the cells. The light was so dim that, on average, only a single melanopsin molecule in each cell was activated by capturing a photon. They found that each activated melanopsin molecule
'/>"/>

Contact: Maryalice Yakutchik
myakutc1@jhmi.edu
443-287-2251
Johns Hopkins Medical Institutions
Source:Eurekalert

Page: 1 2 3

Related biology news :

1. A novel X-ray source could be brightest in the world
2. Bright lights: Mystery of glowing antibody solved by Scripps research scientists
3. Researchers set new record for brightness of quantum dots
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:9/29/2014)... For decades, planetary geologists have speculated that glaciers ... 2000-mile-long chasm that constitutes the Grand Canyon of ... that might have been carved by past glaciers ... observations have remained highly controversial and contested. ... College and the Freie Universitaet Berlin has identified ...
(Date:9/29/2014)... of Pangea was starting to break up and dog-sized dinosaurs ... called phytosaurs and rauisuchids were at the top of the ... predators didn,t interact much as the former was king of ... ideas are changing, thanks largely to the contents of a ... in the German journal Naturwissenschaften , Stephanie ...
(Date:9/29/2014)... Institute (DOE JGI), a DOE Office of Science ... have been selected for the 2015 Community Science ... waters, and from plant root micro-ecosystems, to the ... the CSP 2015 projects portfolio highlights diverse environments ... , "These projects catalyze JGI,s strategic shift in ...
Breaking Biology News(10 mins):Glaciers in the Grand Canyon of Mars? 2Glaciers in the Grand Canyon of Mars? 3Glaciers in the Grand Canyon of Mars? 4Glaciers in the Grand Canyon of Mars? 5Glaciers in the Grand Canyon of Mars? 6Glaciers in the Grand Canyon of Mars? 7Glaciers in the Grand Canyon of Mars? 8Glaciers in the Grand Canyon of Mars? 9Tooth buried in bone shows prehistoric predators tangled across land, sea 22015 DOE JGI's science portfolio delves deeper into the Earth's data mine 22015 DOE JGI's science portfolio delves deeper into the Earth's data mine 32015 DOE JGI's science portfolio delves deeper into the Earth's data mine 42015 DOE JGI's science portfolio delves deeper into the Earth's data mine 52015 DOE JGI's science portfolio delves deeper into the Earth's data mine 62015 DOE JGI's science portfolio delves deeper into the Earth's data mine 72015 DOE JGI's science portfolio delves deeper into the Earth's data mine 82015 DOE JGI's science portfolio delves deeper into the Earth's data mine 9
... 2012 Millions of people worldwide suffer from a ... triggered by nerve damage. Precisely how this pain persists ... ineffective. But a team led by scientists from The ... metabolomics, has now discovered a major clue: dimethylsphingosine (DMS), ...
... researchers of Hospital del Mar and its research institute, ... pharmacological resistance to cancer. This new mechanism is a ... receptor) causing resistance to treatment using a drug called ... The study proves that, both in lab models ...
... work with engines traveling on straight tracks, a team ... Oxford have successfully used DNA building blocks to construct ... tracks with multiple switches. The findings, published in the ... Nanotechnology , are expected to lead to further developments ...
Cached Biology News:Scripps Research scientists provide new understanding of chronic pain 2Scripps Research scientists provide new understanding of chronic pain 3Identified a cause of resistance to colon cancer treatment 2
(Date:9/29/2014)... , Sept. 29, 2014  Ten of the ... of cartilage repair, regeneration, allograft reconstruction and research ... the world gathered to discuss the future of ... of Regenerative Medicine symposium, Cartilage Regeneration: State ... included Orthopedic Biosurgery, Minced Juvenile Allograft, and State ...
(Date:9/29/2014)... a range of resource and environmental problems. Using ... and a clever recycling strategy, Uppsala researchers have ... Their study will be presented soon in the ... our discovery can open several doors to more ... future, says Daniel Brandell, Associate Professor at the ...
(Date:9/29/2014)... 29, 2014 ACEA Biosciences, Inc. ... the 2014 iCELLigence Research Grant for his proposal ... instrument is an impedance based real-time label-free cellular ... Department of Biomedical Engineering at Yale University currently ... projects in Professor Rong Fan's laboratory ...
(Date:9/29/2014)... 2014 METTLER TOLEDO’s new line of ... and precision balances as well as automated ... Users can carry out their daily weighing tasks worry ... balances deliver consistently reliable and compliant results, thanks to ... One of the biggest challenges in analytical and micro-analytical ...
Breaking Biology Technology:World Renowned Experts Discuss Future Of Cartilage Regeneration 2World Renowned Experts Discuss Future Of Cartilage Regeneration 3Smart, eco-friendly new battery to solve problems 2ACEA Biosciences, Inc. Awards Yale University Researcher the iCELLigence Research Grant 2New Line of XPE Balances from METLER TOLEDO is Designed for High Performance and Ease of Compliance 2
... accuracy: DNA vaccines that home in on DCs are ... develop new vaccines against infectious diseases is DNA vaccination. ... vaccine, the body converts the information in the DNA ... However, current DNA vaccines induce relatively weak immune responses ...
... UK, 6 March 2008 Elsevier, the world-leading ... and services, announced today Hybrid Materials 2009: The ... which will take place in Tours, France, 15-19 ... has experienced a 14% annual growth in published ...
... DNDN ) will release its fourth quarter financial results on,Thursday, March ... PT; 11:00 a.m. ET to review fiscal year 2007 financial results,and ... follows:, Time: 11:00 AM ... March 13, 2008 Dial-in: 1-877-548-7901 (domestic) or +1-719-325-4844 ...
Cached Biology Technology:JCI online early table of contents: March 6, 2008 2JCI online early table of contents: March 6, 2008 3JCI online early table of contents: March 6, 2008 4Hybrid materials: Exciting interdisciplinary field offering future solutions for industry 2-Dendreon to Hold Conference Call on Thursday, March 13, 2008 at 11:00 AM ET- 2
BD Falcon 850 cm Smooth-surface TufRol Roller Bottle, tissue-culture treated polystyrene, blow-molded one-piece design, with easy on/off non-vented cap, packed in double bag. (20/ca) Packaging: ...
Four siRNAs targeting your gene of interest, providing gene silencing with 100% satisfaction guaranteed High knockdown potency , High specificity for minimal off-target effects , Flexible siR...
... isopropyl ester (15(R)-17-phenyl trinor PGF2α isopropyl ... both a double bond at 13,14 ... at C-15. Similar to 15(S)-latanoprost, 15(R)-17-phenyl ... potential impurity in most commercial preparations ...
... CLS number is a new product number, ... If showing no availability yet, please order ... contact customer service for assistance. ... Dim: surface area 21 cm 2 ...
Biology Products: