(Press-News.org) This news release is available in German.
Scientists from the Max Planck Institute for Biological Cybernetics in Tübingen, using miniaturised high-speed cameras and high-speed behavioural tracking, discovered that rats move their eyes in opposite directions in both the horizontal and the vertical plane when running around. Each eye moves in a different direction, depending on the change in the animal's head position. An analysis of both eyes' field of view found that the eye movements exclude the possibility that rats fuse the visual information into a single image like humans do. Instead, the eyes move in such a way that enables the space above them to be permanently in view – presumably an adaptation to help them deal with the major threat from predatory birds that rodents face in their natural environment.
Like many mammals, rats have their eyes on the sides of their heads. This gives them a very wide visual field, useful for detection of predators. However, three-dimensional vision requires overlap of the visual fields of the two eyes. Thus, the visual system of these animals needs to meet two conflicting demands at the same time; on the one hand maximum surveillance and on the other hand detailed binocular vision.
The research team from the Max Planck Institute for Biological Cybernetics have now, for the first time, observed and characterised the eye movements of freely moving rats. They fitted minuscule cameras weighing only about one gram to the animals' heads, which could record the lightning-fast eye movements with great precision. The scientists also used another new method to measure the position and direction of the head, enabling them to reconstruct the rats' exact line of view at any given time.
The Max Planck scientists' findings came as a complete surprise. Although rats process visual information from their eyes through very similar brain pathways to other mammals, their eyes evidently move in a totally different way. "Humans move their eyes in a very stereotypical way for both counteracting head movements and searching around. Both our eyes move together and always follow the same object. In rats, on the other hand, the eyes generally move in opposite directions," explains Jason Kerr from the Max Planck Institute for Biological Cybernetics.
In a series of behavioural experiments, the neurobiologists also discovered that the eye movements largely depend on the position of the animal's head. "When the head points downward, the eyes move back, away from the tip of the nose. When the rat lifts its head, the eyes look forward: cross-eyed, so to speak. If the animal puts its head on one side, the eye on the lower side moves up and the other eye moves down." says Jason Kerr.
In humans, the direction in which the eyes look must be precisely aligned, otherwise an object cannot be fixated. A deviation measuring less than a single degree of the field of view is enough to cause double vision. In rats, the opposing eye movements between left and right eye mean that the line of vision varies by as much as 40 degrees in the horizontal plane and up to 60 degrees in the vertical plane. The consequence of these unusual eye movements is that irrespective of vigorous head movements in all planes, the eyes movements always move in such a way to ensure that the area above the animal is always in view simultaneously by both eyes –something that does not occur in any other region of the rat's visual field.
These unusual eye movements that rats possess appear to be the visual system's way of adapting to the animals' living conditions, given that they are preyed upon by numerous species of birds.
Although the observed eye movements prevent the fusion of the two visual fields, the scientists postulate that permanent visibility in the direction of potential airborne attackers dramatically increases the animals' chances of survival.
INFORMATION:
Original publication:
Rats maintain an overhead binocular field at the expense of constant fusion
Damian J.Wallace, David S. Greenberg, Juergen Sawinski, Stefanie Rulla, Giuseppe Notaro, & Jason N. D. Kerr
Nature, online May 26, 2013: doi:10.1038/nature12153
Rats have a double view of the world
Rodents move their eyes in opposite directions, thereby always keeping an eye on the airspace above them
2013-05-28
ELSE PRESS RELEASES FROM THIS DATE:
How do plants grow toward the light?
2013-05-28
The growth of plants toward light is particularly important at the beginning of their lifecycle. Many seeds germinate in the soil and get their nutrition in the dark from their limited reserves of starch and lipids. Reaching for the surface, the seedlings rapidly grow upwards against the gravitational pull, which provides an initial clue for orientation. With the help of highly sensitive light-sensing proteins, they find the shortest route to the sunlight – and are even able to bend in the direction of the light source.
"Even mature plants bend toward the strongest light. ...
When perks don't work
2013-05-28
New research from UBC's Sauder School of Business reveals that giving a free bump in service can backfire for retailers if the perk is given randomly in front of others.
The new paper shows that consumers experience social discomfort when singled out for spontaneous special treatment, which may cause them to close their wallets.
"Managerial wisdom guiding service and retail industries assumes that consumers get an uptick in esteem when they're allowed to skip a queue or get an upgrade," says Assistant Professor JoAndrea Hoegg, a co-author of the forthcoming study to ...
Long-term benefits of selective dorsal rhizotomy in children with spastic cerebral palsy
2013-05-28
Charlottesville, VA (May 28, 2013). Selective dorsal rhizotomy (SDR) is a surgical procedure used to treat spasticity in some children with spastic cerebral palsy. This procedure appears to be effective, but for how long? Researchers from Montreal, Quebec, Canada,* set out to find the answer to this question by studying data from the McGill University Rhizotomy Database on 102 pediatric patients with long-term follow-up. The researchers found that, in the majority of children with spastic cerebral palsy, the benefits of SDR last throughout adolescence and into early adulthood. ...
Family studies suggest rare genetic mutations team up to cause schizophrenia
2013-05-28
Using a novel method of analyzing genetic variations in families, researchers at Johns Hopkins have found that individually harmless genetic variations affecting related biochemical processes may team up to increase the risk of schizophrenia. They say their findings, reported May 28 in Translational Psychiatry, bring some clarity to the murky relationship between genetics and schizophrenia, and may lead to a genetic test that can predict which medications will be effective for individual patients.
"It's long been clear that schizophrenia runs in families, but schizophrenia ...
African-Americans experience longer delays between diagnosis and treatment of prostate cancer
2013-05-28
Among men with prostate cancer, African Americans experience longer treatment delays after being diagnosed than Caucasians. That is the finding of an analysis published early online in CANCER, a peer-reviewed journal of the American Cancer Society. The study suggests that efforts are needed to reduce racial disparities in prostate cancer care in order to provide earlier treatment for African Americans.
To see if there is a difference in the time from cancer diagnosis to initiation of treatment for African American men compared with Caucasian men with prostate cancer, ...
Findings may help overcome hurdle to successful bone marrow transplantation
2013-05-28
Blood diseases such as leukemia, multiple myeloma, and myelodysplasia can develop from abnormal bone marrow cells and a dysfunctional bone marrow microenvironment that surrounds these cells. Until now, researchers have been unable to replace the cells that make up the bone marrow microenvironment. Researchers reporting in the May 28 issue of the Cell Press journal Developmental Cell have found that eliminating a gene in the cells found in this microenvironment causes them to die, therefore enabling donor cells to replace them. In addition to providing a better understanding ...
Engineered stem cell advance points toward treatment for ALS
2013-05-28
MADISON, Wis. — Transplantation of human stem cells in an experiment conducted at the University of Wisconsin-Madison improved survival and muscle function in rats used to model ALS, a nerve disease that destroys nerve control of muscles, causing death by respiratory failure.
ALS (amyotrophic lateral sclerosis) is sometimes called "Lou Gehrig's disease." According to the ALS Association, the condition strikes about 5,600 Americans each year. Only about half of patients are alive three years after diagnosis.
In work recently completed at the UW School of Veterinary ...
Dealing with 'crap' to improve water quality
2013-05-28
RIVERSIDE, Calif. (http://www.ucr.edu) — To better understand how bacteria impact the environment a former University of California, Riverside graduate student spent nearly a year building a system that replicates a human colon, septic tank and groundwater and "fed" the colon three times a day during weeklong experiments to simulate human eating.
Ian Marcus, who recently earned his Ph.D. from the UC Riverside Bourns College of Engineering, said discussion of the research often left people a bit perplexed.
"People would give a kind-of-interested-but-definitely-don't-talk-about-it-during-dinner ...
White Mountains hikers often underprepared
2013-05-28
PROVIDENCE, R.I. [Brown University] — Hikers in New Hampshire's White Mountain National Forest often hit the trail less prepared than they should be, according to a study that gauged readiness by how many of 10 essential items the hikers brought along.
Young and inexperienced hikers were most likely to lack multiple items recommended by the State of New Hampshire's HikeSafe program, according to a paper in press at the journal Wilderness & Environmental Medicine. Hikers were also less likely to prepare fully if they were planning a short hike, even though those can quickly ...
Cold climate wind energy showing huge potential
2013-05-28
Wind energy capacity is growing rapidly in the cold climates of the world. According to the latest forecasts, between 45 and 50 gigawatts of wind energy will be built in cold climates by 2017, which would mean an increase of as much as 72 per cent since the end of 2012 and investments amounting to approximately EUR 75 billion.
"This is a huge opportunity," says Research Scientist Tomas Wallenius from VTT Technical Research Centre of Finland. "There has been a lot of talk about the potential of offshore wind power, but the market for cold climate wind energy is more than ...
LAST 30 PRESS RELEASES:
New strategies to enhance chiral optical signals unveiled
Cambridge research uncovers powerful virtual reality treatment for speech anxiety
2025 Gut Microbiota for Health World Summit to spotlight groundbreaking research
International survey finds that support for climate interventions is tied to being hopeful and worried about climate change
Cambridge scientist launches free VR platform that eliminates the fear of public speaking
Open-Source AI matches top proprietary model in solving tough medical cases
Good fences make good neighbors (with carnivores)
NRG Oncology trial supports radiotherapy alone following radical hysterectomy should remain the standard of care for early-stage, intermediate-risk cervical cancer
Introducing our new cohort of AGA Future Leaders
Sharks are dying at alarming rates, mostly due to fishing. Retention bans may help
Engineering excellence: Engineers with ONR ties elected to renowned scientific academy
New CRISPR-based diagnostic test detects pathogens in blood without amplification
Immunotherapy may boost KRAS-targeted therapy in pancreatic cancer
Growing solar: Optimizing agrivoltaic systems for crops and clean energy
Scientists discover how to reactivate cancer’s molecular “kill switch”
YouTube influencers: gaming’s best friend or worst enemy?
uOttawa scientists use light to unlock secret of atoms
NJIT mathematician to help map Earth's last frontier with Navy grant
NASA atmospheric wave-studying mission releases data from first 3,000 orbits
‘Microlightning’ in water droplets may have sparked life on Earth
Smoke from wildland-urban interface fires more deadly than remote wildfires
What’s your body really worth? New AI model reveals your true biological age from 5 drops of blood
Protein accidentally lassos itself, helping explain unusual refolding behavior
With bird flu in raw milk, many in U.S. still do not know risks of consuming it
University of Minnesota research team awarded $3.8 million grant to develop cell therapy to combat Alzheimer’s disease
UConn uncovers new clue on what is leading to neurodegenerative diseases like Alzheimer’s and ALS
Resuscitation in out-of-hospital cardiac arrest – it’s how quickly it is done, rather than who does it
A closer look at biomolecular ‘silly putty’
Oxytocin system of breastfeeding affected in mothers with postnatal depression
Liquid metal-enabled synergetic cooling and charging: a leap forward for electric vehicles
[Press-News.org] Rats have a double view of the worldRodents move their eyes in opposite directions, thereby always keeping an eye on the airspace above them