Navigation Links
Blind humans lacking rods and cones retain normal responses to non-visual effects of light
Date:12/13/2007

In addition to allowing us to see, the mammalian eye also detects light for a number of non-visual phenomena. A prime example of this is the timing of the sleep/wake cycle, which is synchronized by the effects of light on the circadian pacemaker in the hypothalamus.

In a study published online on December 13th in Current Biology, researchers have identified two totally blind humans whose non-visual responses to light remain intact, suggesting that visual and non-visual responses to light are functionally distinct. Indeed, this separation was suggested by earlier studies in mice that demonstrated that circadian rhythms and other non-visual responses remain sensitive to light in the absence of rods and cones, the two photoreceptor types that are responsible for vision.

It turns out that mammals have an additional light-sensitive photoreceptor in the retinal ganglion cell layer (pRGCs) that is directly sensitive to light and is primarily responsible for mediating these responses. These cells are most sensitive to short-wavelength light with a peak sensitivity at ~480 nm, in the visible blue light range. While these studies and others in sighted subjects suggested that this non-rod, non-cone photoreceptor might play an important role in human photoreception, this had yet to demonstrated unequivocally until now.

To address whether the cells identified in rodents and primates also exist in humans, Zaidi and colleagues first had to find patients who lacked functional rods and cones, but retained pRGCsa formidable task, given that fewer than 5% of totally blind people are thought to retain this response.

This group of researchers was able to identify two such rare patients, allowing them to perform a series of complementary experiments to address whether non-visual responses are possible in the absence of rods and cones and to determine the most effective wavelength, or color, of light that induced a response. In the first patient
'/>"/>

Contact: Cathleen Genova
cgenova@cell.com
617-397-2802
Cell Press
Source:Eurekalert

0

GOOD

Page: 1 2 3

Related medicine news :

1. Can brain-injured, partially-blind stroke patients regain some of their lost vision?
2. New discovery may improve treatment of one of the worlds leading causes of blindness
3. Verizon Awards $1.5 Million Grant to Expand American Foundation for the Blinds Web Site for Seniors With Age-Related Vision Loss
4. Diabetes: A Top Cause of Blindness Among Adults
5. Blinded by the Light? Vision Problems and Visual Discomfort Make Driving in the Dark Difficult, Uncomfortable for Most Americans
6. Survey Confirms Americans Have a True Blind Spot Regarding Their Eye Health - and the Real Danger of UV Rays
7. STEP HIV vaccine study to be unblinded
8. Gene therapy safety trial for childhood blindness under way
9. National Federation of the Blind to Award $100,000
10. Investigational Agent Targeting Metabotropic Glutamate 2/3 Receptors Demonstrates Antipsychotic Activity in Humans, Study in Nature Medicine Finds
11. Toddler Study Proves Humans Outsmart Apes
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/21/2013)... maltreatment are 36% more likely to be obese in ... study by King,s College London. The authors estimate that ... child maltreatment could avoid 1 case of adult obesity. ... data from 190,285 individuals from 41 studies worldwide, published ... childhood maltreatment (physical, sexual or emotional abuse or neglect) ...
(Date:5/21/2013)... D.C (PRWEB) May 21, 2013 The ... pleased to announce four transitions for its Board of ... of the Western Michigan University School of Medicine, has ... of Medical Education at the University of California San ... President/Chief Executive Officer of the Nebraska Medical Center, is ...
(Date:5/21/2013)... May 21, 2013 It took Willie ... prison for his sixth time on a fifteen year ... warden Frank Eyman to trust him enough to allow ... other addicted inmates. “NarcoNon” Willie intended to name his ... finally get permission and did start up that class. ...
(Date:5/21/2013)... Montclair, New Jersey (PRWEB) May 21, 2013 ... is a fierce advocate for walkable neighborhoods. One of ... effect walkable environments have on health. In light of ... States, Panza urges home buyers to consider walkable living. ... posted May 2, 2013 spotlights walkable neighborhoods as ...
(Date:5/21/2013)... May 21, 2013 Dr. James C. ... Director of the Sarcoma Division of the John Theurer ... Jersey has been named one of the top 13 ... Week. Dr. Wittig is one of approximately 125 ... list was created by surveying thought leaders in the ...
Breaking Medicine News(10 mins):Health News:Child maltreatment increases risk of adult obesity 2Health News:New Board of Directors Leadership for The Match- National Resident Matching Program® 2Health News:New Board of Directors Leadership for The Match- National Resident Matching Program® 3Health News:Narconon Releases Report on its Very First Narconon Program, the First of 23 Reviews or Evaluations of Results up to 2009 2Health News:Narconon Releases Report on its Very First Narconon Program, the First of 23 Reviews or Evaluations of Results up to 2009 3Health News:Narconon Releases Report on its Very First Narconon Program, the First of 23 Reviews or Evaluations of Results up to 2009 4Health News:Narconon Releases Report on its Very First Narconon Program, the First of 23 Reviews or Evaluations of Results up to 2009 5Health News:New Jersey Realtor, Lina Panza, Advocates Walkable Neighborhoods to Combat Childhood Obesity 2Health News:New Jersey Realtor, Lina Panza, Advocates Walkable Neighborhoods to Combat Childhood Obesity 3Health News:James C. Wittig, MD, Selected as one of America's Top 13 Orthopaedic Oncologists 2Health News:James C. Wittig, MD, Selected as one of America's Top 13 Orthopaedic Oncologists 3
... to check cases of polio that have more than doubled ... country reported 155 cases, as against 66 last year. Most ... ,"The committee comprising doctors, health workers and health ... NGOs," Health Minister Ambumani Ramadoss told IANS on the sidelines ...
... is its own place, and in itself, can make heaven ... three centuries ago. Though delicate as the most exquisite silk ... can withstand the strongest forces in this universe. Yet when ... is marred. Heaven unravels deep within and yet another perfect ...
... or brain injury, the simplest movements like putting one ... arm to open a door can be daunting for ... to traditional physical rehabilitation and medical treatment. ,A ... implanted in the abdomen and controlled remotely can change ...
... tears of a Jharkhand girl who complained that she wept ... Medical Science (AIIMS) here Wednesday.// ,Savitri, a 13-year-old girl ... her tears for the last two years. She was brought ... investigation has not found any problem in her eyes. But ...
... unit is said to make patients wait longer than anywhere ... ,This news has only added salt to the wound ... at the ERI following its branding as one of the ... figures have shown that more than a third of patients ...
... asthmatic people to control their symptoms will be stressed upon, ... hurler from Kilkenny, footballers Colin Moran from Dublin, Tommy Griffin ... problem have a negative impact on their lives. ... They will participate in information roadshow that will be conducted ...
Cached Medicine News:Health News:Mind in a Bind – Alternative Intervention 2Health News:Mind in a Bind – Alternative Intervention 3Health News:Computer Assisted Neuro-Rehabilitation Devices Way of the Future 2Health News:Inordinately Long Waiting Times at A&E Infirmary 2
(Date:5/20/2013)... , May 21, 2013   ... where world,s health ministers gather to address the large ... Mental and neurological disorders (MNDs) affect 700 million people ... disease (NCD) burden ,Do You Mind?, helps ... role each can play to collectively address MNDs , ...
(Date:5/20/2013)... 20, 2013  Volcano Corporation (NASDAQ: VOLC ... therapy tools designed to enhance the diagnosis and treatment ... will highlight its efforts to expand research and innovation ... (FFR) and iFR ® (Instant Wave-Free Ratio™) 1 ... events at EuroPCR 2013 in Paris ...
(Date:5/20/2013)... , May 20, 2013  B. Braun Medical ... and environmental safety with products, services and education ... feature its innovative Outlook® 400ES and Space Infusion ... capabilities at the American Association of Critical-Care Nurses ... Boston Convention Center. ...
Breaking Medicine Technology:Research-based Pharmaceutical Industry Launches 'Do You Mind?' Campaign to Fight Mental and Neurological Disorders 2Volcano to Highlight its Physiology Expansion Efforts at EuroPCR 2013 2Volcano to Highlight its Physiology Expansion Efforts at EuroPCR 2013 3Volcano to Highlight its Physiology Expansion Efforts at EuroPCR 2013 4B. Braun Committed To Improving Patient Safety 2
... Company (NASDAQ: STAA ) today announced that it will release ... Wednesday, May 2, 2012 after the market close. ... on Wednesday, May 2, 2012 at 4:30 p.m. Eastern / ... Company,s first quarter 2012 results and recent corporate developments. The dial-in number ...
... first center dedicated to treating spine patients with the ... today, April 25, in Chicago. The Midwest Orthopaedics at ... in MOR,s new, state-of-the-art building, 1611 W. Harrison ... Phillips and Kern Singh, board-certified orthopedic spine surgeons ...
Cached Medicine Technology:STAAR Surgical Announces First Quarter 2012 Results Release Date and Conference Call and Webcast 2Midwest Orthopaedics at Rush Minimally Invasive Spine Institute Opens Today 2
... an all-original guide prepared specifically ... Derived from "PocketMedicine/Internal Medicine", it ... to those training in the ... who are frequently the first ...
The Nervous System Flash Cards product uses the time tested content and images from BryanEdwards.com and displays the necessary images to demonstrate the nervous system....
Neurology, neurosurgery, and internal medicine residents and practitioners will find this mobile solution an essential reference for their day-to-day practice....
... those involved with healthcare decisions to keep ... evidence in their field of interest - ... as the volume of evidence increases. Cochrane ... best single source available for continually updated ...
Medicine Products: