Monkeys” fighting behaviour could give insights into human wars

London, May 14 (ANI): A study on monkeys’ choices while deciding to fight or remaining at peace could help shed light on human wars, says a new study.

Competition for resources is often assumed to be a main cause of conflict in both humans and other animals, says Jessica Flack at the Santa Fe Institute in New Mexico, but that might be wrong, reports New Scientist.

“We find that fighting is based on memories of what other individuals did last,” she added.

The researchers analysed data from 160 days of field observations of a group of 84 pigtailed macaques at the Yerkes National Primate Research Center in Lawrenceville, Georgia.

The team paid particular attention to which animals fought and how long each fight lasted.

Instead of explaining the monkey”s fighting ways by dreaming up a strategy based, for example, on the reward value of winning a fight for food or a mate, the researchers decided to look for strategies suggested by the data alone.

They made no assumption about the reasons for the monkeys” behaviour and looked only at patterns of behaviour leading up to fights.

Thus, they could determine the relative importance of the factors that led up to a fight.

They found that the strategy that best explained involvement in a fight was one in which decisions were based on the presence or absence of pairs of other monkeys.

This suggests that social dynamics play a central role.

Flack said that previous work has shown that monkeys often react to changes in the social structure of their group.

A monkey might decide to fight because a rival was gaining dominance, for example, or to defend another monkey that they wanted to make into an ally.

The new finding that previous conflicts shape future decisions suggests that fights may not be directly linked to immediate competition for resources.

However, in the long term, the motivations behind the strategy are linked to the fight for status and the access to resources that status brings, said Flack.

A better understanding of the real-world strategies used by monkeys could help predict the shape of future conflicts. (ANI)

Regular aerobic exercise keeps the brain healthy

Washington, Apr 27 (ANI): Regular aerobic exercise improves blood flow to the brain and speeds learning process, says a new study.

The study led by researchers from the University of Pittsburgh School of Medicine is the first to examine these relationships in a non-human primate model.

The finding is available in the journal Neuroscience.

While there is ample evidence of the beneficial effects of exercise on cognition in other animal models, such as the rat, it has been unclear whether the same holds true for people, said senior author Judy L. Cameron, Ph.D., a psychiatry professor at Pitt School of Medicine and a senior scientist at the Oregon National Primate Research Center at Oregon Health and Science University. Testing the hypothesis in monkeys can provide information that is more comparable to human physiology.

“We found that monkeys who exercised regularly at an intensity that would improve fitness in middle-aged people learned to do tests of cognitive function faster and had greater blood volume in the brain”s motor cortex than their sedentary counterparts,” Dr. Cameron said. “This suggests people who exercise are getting similar benefits.”

To reach the conclusion, researchers trained adult female cynomolgus monkeys to run on a human-sized treadmill at 80 percent of their individual maximal aerobic capacity for one hour each day, five days per week, for five months. Another group of monkeys remained sedentary, meaning they sat on the immobile treadmill, for a comparable time. Half of the runners went through a three-month sedentary period after the exercise period. In all groups, half of the monkeys were middle aged (10 to 12 years old) and the others were more mature (15 to 17 years old). Initially, the middle-aged monkeys were in better shape than their older counterparts, but with exercise, all the runners became more fit.

During the fifth week of exercise training, standardized cognitive testing was initiated and then performed five days per week until week 24. In a preliminary task, the monkeys learned that by lifting a cover off a small well in the testing tray, they could have the food reward that lay within it. In a spatial delay task, a researcher placed a food reward in one of two wells and covered both wells in full view of the monkey. A screen was lowered to block the animal”s view for a second, and then raised again. If the monkey displaced the correct cover, she got the treat. After reliably succeeding at this task, monkeys that correctly moved the designated one of two different objects placed over side-by-side wells got the food reward that lay within it.

“Monkeys that exercised learned to remove the well covers twice as quickly as control animals,” Dr. Cameron said. “Also, they were more engaged in the tasks and made more attempts to get the rewards, but they also made more mistakes.”

She noted that later in the testing period, learning rate and performance was similar among the groups, which could mean that practice at the task will eventually overshadow the impact of exercise on cognitive function.

When the researchers examined tissue samples from the brain”s motor cortex, they found that mature monkeys that ran had greater vascular volume than middle-aged runners or sedentary animals. But those blood flow changes reversed in monkeys that were sedentary after exercising for five months.

“These findings indicate that aerobic exercise at the recommended levels can have meaningful, beneficial effects on the brain,” Dr. Cameron said. “It supports the notion that working out is good for people in many, many ways.” (ANI)

Environment may influence apes” ability to understand declarative communication

Washington, March 16 (ANI): A new study indicates that apes may have the potential for understanding declarative communication and this potential may be achieved in specific environments.

Numerous studies have tried to determine if great apes (for example, chimpanzees and bonobos) are able to understand declarative communication, but results have been mixed.

In the new research, scientists Heidi Lyn and William Hopkins from Agnes Scott College and Jamie Russell from the Yerkes National Primate Research Center examined if exposure to different human communicative environments would affect understanding of declarative signals in chimpanzees and bonobos.

Three groups of apes were tested in this study. One group consisted of chimpanzees that had been raised in standard laboratory housing; although they had regular contact with humans, these interactions were limited to basic animal-care contexts such as feeding.

The other two groups of apes consisted of chimpanzees and bonobos that had been raised in socio-linguistically rich environments, where they were routinely exposed to complex communicative interactions with humans.

In the current experiment, the apes participated in an object-choice task – they had to choose between two containers, one of which contained a food reward.

The placement of the food in one of the containers was hidden from the apes, and a researcher indicated the correct container by pointing, vocalizing, or both.

The results indicate interesting differences between chimps and bonobos raised in socio-linguistically rich environments and chimps raised in standard laboratory housing.

The bonobos and chimps that had been reared in the highly communicative environments performed significantly better than chimps that had been reared in standard laboratory settings in the pointing, vocalizing, and pointing-and-vocalizing conditions.

Further analysis revealed that the best results occurred when the researcher simultaneously pointed and vocalized towards the correct container. This finding supports earlier studies that suggest visual cues enhance performance on auditory tasks.

“Because the ability to acquire declarative comprehension is common to both apes and humans, researchers must look elsewhere for a candidate biological change that allowed for the evolution of human language and cognition,” the authors said.

The study has been reported in Psychological Science, a journal of the Association for Psychological Science. (ANI)

HIV uses several routes to escape immune system pressure

Washington, September 19 (ANI): Researchers at the Emory Vaccine Center have shown that HIV relies upon a number of strategies rather than use any preferred escape route to escape immune system pressure.

The human immune system has the ability to temporarily overpower HIV in early infection.

Studies conducted in the recent past have shown that most newly infected patients develop neutralizing antibodies. These are blood proteins that glob onto the virus and would allow patients to defend themselves – if they were facing only one target.

However, the problem occurs when HIV mutates, and disguises itself enough to get away from the antibodies. The virus eventually wears down the immune system into exhaustion.

The Emory team’s findings attain significance as they suggest that even if any scientist succeeds in identifying a vaccine component that can stimulate neutralizing antibodies, HIV’s capacity for rapid mutation could still be a confounding factor.

Dr. Cynthia Derdeyn, associate professor of pathology at Emory University School of Medicine, Emory Vaccine Center and Yerkes National Primate Research Center, says that a single type of neutralizing antibody may not be enough to contain HIV.

“These neutralizing antibodies work really well – they hit the virus fast and hard. But so far, every time we look, the virus escapes,” she says.

During the study, the researchers took blood samples from the participants a few weeks after infection occurred, and then later as two participants’ immune responses continued.

They isolated individual viruses over the first two years of HIV infection, and tested how well the patients’ own antibodies could neutralize them.

“In one patient where we had very early samples, there was evidence that neutralizing antibody came up within weeks, and that’s earlier than what was previously thought,” Derdeyn says.

In both patients, some viruses mutated part of their outer proteins so that after the mutation, an enzyme would be likely to attach a sugar molecule to it.

Though the sugar molecule interferes with antibody attack, this tactic, known as the “glycan shield”, was not observed in all cases.

Other viruses mutated the part of the outer protein that the neutralizing antibodies stick to directly. In both patients, many changes in the virus’ genetic code were necessary for escape.

“We need to understand early events in the immune response if we are going to figure out what a potential vaccine should have in it. What we can show is that even in one patient, several escape strategies are going on,” Derdeyn says.

According to her, that means that in order to be immune to HIV infection, someone may need to have several types of neutralizing antibodies ready to go.

Seeing how the virus mutates will allow researchers to choose the best parts to put in a vaccine, she says.

The results are online and scheduled for publication in the September issue of the journal Public Library of Science Pathogens.(ANI)

Early life nurturing influences social behaviors in adulthood

Washington, Sept 1 (ANI): A new study, conducted by researchers at the Yerkes National Primate Research Center, Emory University, has shown that early life nurturing impacts later life relationships.

The researchers used prairie voles as a model to understand the neurochemistry of social behavior.

Prairie voles are small, highly social, hamster-sized rodents that often form stable, life-long bonds between mates.

By influencing early social experience in prairie voles, researchers gained insight into what aspects of early social experience drive diversity in adult social behavior.

In the wild, there is striking diversity in how offspring are reared. Some pups are reared by single mothers, some by both parents and some in communal family groups.

For the study, Todd Ahern, a graduate student in the Emory University Neuroscience Program, and Larry Young, PhD, professor of psychiatry and behavioral sciences at the Yerkes Research Center and Emory University School of Medicine, compared pups raised by single mothers (SM) to pups raised by both parents (BP) to determine the effects of these types of early social environments on adult social behavior.

“Our findings demonstrate that SM- and BP-reared animals experienced different levels of care during the neonatal period and that these differences significantly influenced bonding social behaviors in adulthood,” Ahern said.

Young added: “These results suggest naturalistic variation in social rearing conditions can introduce diversity into adult nurturing and attachment behaviors. SM-raised pups were slower to make life-long partnerships, and they showed less interest in nurturing pups in their communal families.

The researchers also found differences in the oxytocin system. Oxytocin is best known for its roles in maternal labor and suckling, but, more recently, it has been tied to prosocial behavior, such as bonding, trust and social awareness.

“Very simply, altering their early social experience influenced adult bonding,” Ahern said.

Further studies will look at the altered oxytocin levels in the brain to determine how these hormonal changes affect relationships.

The study is currently available online in a special edition of Frontiers in Behavioral Neuroscience. (ANI)

Gene breakthrough could banish inherited diseases

London, Aug 26 (ANI): Researchers at Oregon Health and Science University’s Oregon National Primate Research Center (ONPRC) have developed a new technique that could banish a host of crippling inherited diseases forever.

The landmark research raises the prospect of wiping out diseases passed on from mothers to their children through mutated DNA in cell mitochondria.

“We believe this discovery in nonhuman primates can rapidly be translated into human therapies aimed at preventing inherited disorders passed from mothers to their children through the mitochondrial DNA, such as certain forms of cancer, diabetes, infertility, myopathies and neurodegenerative diseases,” said Shoukhrat Mitalipov, from Oregon Health and Science University (OHSU).

Mitochondria are structures that are found in all cells that provide energy for cell growth and metabolism, which is why they are often called the cell’s “power plant.”

The structures produce energy to power each individual cell. Mitochondria also carry their own genetic material.

When an egg cell is fertilized by a sperm cell during reproduction, the embryo almost exclusively inherits the maternal mitochondria present in the egg. This means that any disease-causing genetic mutations that a mother carries in her mitochondrial DNA can be passed on to her offspring.

OHSU researchers’ method transfers the mother’s chromosomes to a donated egg that has had its chromosomes removed, but which has healthy mitochondria, thereby preventing the disease from being passed on to one’s offspring.

During the research, scientists collected groups of unfertilized eggs from two female rhesus macaque monkeys (monkeys A and B). They then removed the chromosomes, which contain the genes found in the cell nucleus, from the eggs of monkey B, and then transplanted the nuclear genes from the eggs of monkey A into the eggs of monkey B.

Then the eggs from monkey B, which now contained their own mitochondria but monkey A’s nuclear genes, were fertilized. The fertilized eggs developed into embryos that were implanted in surrogate monkeys.

The initial implantation of two embryos resulted in the birth of healthy twin monkeys. These monkeys are the world’s first animals derived by spindle transfer.

Follow-up testing showed that there was little to no trace of cross-animal mitochondrial transfer using this procedure. This shows that the researchers were successful in isolating nuclear genetic material from mitochondrial genetic material during the transfer process.

“In theory, this research has demonstrated that it is possible to use this therapy in mothers carrying mitochondrial DNA diseases so that we can prevent those diseases from being passed on to their offspring,” Mitalipov said.

“We believe that with the proper governmental approvals, our work can rapidly be translated into clinical trials for humans, and, eventually, approved therapies,” Mitalipov added.

The research has been published in the Aug. 26 advance online edition of the journal Nature. (ANI)

Consuming low calorie diet leads to ‘longer, healthier life’

Washington, July 10 (ANI): Substantially cutting calories from the diet could slow the ageing process and increase life expectancy, according to a decades-long study of monkeys.

Researchers at the University of Wisconsin-Madison, the Wisconsin National Primate Research Center and the William S. Middleton Memorial Veterans Hospital have found that a nutritious but reduced-calorie diet blunts aging and significantly delays the onset of such age-related disorders as cancer, diabetes, cardiovascular disease and brain atrophy.

“We have been able to show that caloric restriction can slow the aging process in a primate species,” says Richard Weindruch, a professor of medicine in the UW-Madison School of Medicine and Public Health who leads the National Institute on Aging-funded study. “We observed that caloric restriction reduced the risk of developing an age-related disease by a factor of three and increased survival.”

During the 20-year course of the study, half of the animals permitted to eat freely have survived, while 80 percent of the monkeys given the same diet, but with 30 percent fewer calories, are still alive.

Begun in 1989 with a cohort of 30 monkeys to chart the health effects of the reduced-calorie diet, the study expanded in 1994 with the addition of 46 more rhesus macaques. All of the animals in the study were enrolled as adults at ages ranging from 7 to 14 years.

Today, 33 animals remain in the study. Of those, 13 are given free rein at the dinner table, and 20 are on a calorie-restricted diet. Rhesus macaques have an average life span of about 27 years in captivity. The oldest animal currently in the study is 29 years.

Weindruch notes that in terms of overall animal health, the restricted diet leads to longer lifespan and improved quality of life in old age.

“There is a major effect of caloric restriction in increasing survival if you look at deaths due to the diseases of aging,” he said.

The study has been published in the journal Science. (ANI)

Monkeys, humans use common brain mechanism to recognize faces

Washington, June 26 (ANI): Scientists have shown for the first time that rhesus monkeys and humans share a specific perceptual mechanism, configural perception, for discriminating among the numerous faces they encounter daily.

The study, conducted by researchers at the Yerkes National Primate Research Center, Emory University, sheds light on the evolution of the critical human social skill of facial recognition, which enables us to form relationships and interact appropriately with others.

“Humans and other social primates need to recognize other individuals and to discriminate kin from non-kin, friend from foe and allies from antagonists,” said lead researcher Robert R. Hampton of the Yerkes National Primate Research Center and Emory’s Department of Psychology.

“Our research indicates the ability to perform this skill probably evolved some 30 million or more years ago in an ancestor humans share with rhesus monkeys,” he added.

The remarkable capability humans have to distinguish among thousands of faces stems from our sensitivity to the unique configuration, or layout, of facial features.

“Because faces share so many features in common – eyes, nose, mouth, etc. – the simple detection of the collection of these features alone would not permit us to tell many faces apart,” Dr. Hampton noted.

“It’s our ability to perceive small changes in the relations among the features that enables us to distinguish thousands of faces and recognize those we know,” he said.

Hampton and his colleagues used the Thatcher Effect, a perceptual illusion named for Margaret Thatcher because it was first demonstrated using an image of the former British prime minister, to determine if rhesus monkeys use configural perception to recognize other monkeys.

In the study, the researchers presented images of six different monkeys to four 4-year-old rhesus macaque monkeys raised for two to three years in large social groups at the Yerkes Research Center.

The researchers “thatcherized” the images of faces by positioning the eyes and mouths upside down relative to the rest of each face.

The researchers presented monkeys with normal images of each face upside down and right side up until the monkeys were bored and ceased looking at the pictures.

They then showed the monkeys the thatcherized faces. In the upright position, the monkeys were surprised by the distorted features and began looking at the pictures again.

On contrary, when the faces were upside down, they were not at all surprised and treated the faces as if nothing had been done to them.

This is similar to the human response to the Thatcher Effect, which shows that when the eyes and mouth are rotated and, thus, distorted, humans surprisingly process the upside-down version of the image more as a collection of features and with less emphasis on the relations among the features.

As a result, the face appears fairly normal despite being thatcherized. However, when viewed right side up, humans say the image looks awkward or grotesque, demonstrating they clearly see the eyes and mouth have been rotated.

“This study advances our understanding of social processes critical for a healthy and successful social life in primates. Early primates apparently solved the problem of recognizing each others’ faces in this way well before humans arrived on the planet,” Hampton concluded.

The study has been reported in the June 25 online issue of Current Biology. (ANI)