Chemical cues from fathers may be delaying the onset of sexual maturity in daughters, as part of an evolutionary strategy to prevent inbreeding, according to researchers at Penn State. "Biological fathers send out inhibitory chemical signals to their daughters," said Robert Matchock, assistant professor of psychology at Penn State's Altoona Campus. "In the absence of these signals, girls tend to sexually mature earlier." The effect of chemical cues on sexual maturity is common in the animal world, Matchock explained. If the biological father is removed from rodent families, the daughters tend to mature faster, he said. "Recently, experts elsewhere discovered a little-known pheromone receptor gene in the human olfactory system, linking the role of pheromones on menarche, or the first occurrence of menstruation," said Matchock, whose findings are published in the recent issue of the American Journal of Human Biology. "Our results indicate that girls without fathers matured approximately three months before girls whose fathers were present," Matchock said, adding that the data seem to suggest a relationship between length of the father's absence and age of menarche – the earlier the absence, the earlier the menarche.

Keyword: Chemical Senses (Smell & Taste); Sexual Behavior
Link ID: 9326 - Posted: 06.24.2010

Phil McKenna Older people who complain of memory loss – but who still do well on standard memory tests – may genuinely be losing brain tissue, perhaps in advance of the onset of Alzheimer’s disease, researchers have warned. The team examined the brain scans of adults over 60 who said they suffered significant memory deficits, yet scored normal on cognitive tests. The scans revealed a reduction in grey matter density when compared with the scans from people of similar age who did not report memory problems. The finding could lead to earlier detection of Alzheimer’s – something the researchers say is a prerequisite to an effective treatment for the elusive disease. “We are trying to push the window back to earlier diagnosis,” says Andrew Saykin, a psychiatrist and radiologist at Dartmouth Medical School in Lebanon, New Hampshire, US. “There is extensive damage to the brain by the time people meet diagnostics criteria for Alzheimer’s disease. We would like to identify individuals at high risk a decade or two before they develop Alzheimer’s.” Saykin notes that elderly patients who complain of memory loss but do fine on cognitive tests are often dismissed as the “worried well": “These are not people who have occasional trouble remembering a name or word, but whose memory is seriously declining,” Saykin says. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory; Alzheimers
Link ID: 9325 - Posted: 06.24.2010

Researchers believe that they have found how the body protects itself against diseases like Alzheimer's. International experts found a brain enzyme that "snips apart" tangles of a protein linked to a decline in mental abilities and brain cell death. The scientists said that, in the future, drugs could be used to enhance this natural defence mechanism. The research is published in the journal Neuron. A hallmark of Alzheimer's and related diseases are bundles of fibre that are found in the brain's nerve cells. These "tangles", mainly made up of a protein called tau, are thought to be associated with brain cell death. The team of scientists found that an enzyme called puromycin-sensitive aminopeptidase, or PSA, was snipping apart tau proteins in human brain tissue. They also discovered, looking at fruit flies, that higher levels of PSA protected against brain cell death - neurodegeneration, while lower levels speeded up the brain's demise. The researchers concluded that PSA may play a "pivotal" protective role. They said their findings were an "important step forward" in the bid to understand the mechanisms involved in neurodegenerative diseases. In the future, they said, drugs could be used to boost levels of PSA, which in essence would enhance the body's natural defence mechanism. (C)BBC

Keyword: Alzheimers
Link ID: 9324 - Posted: 09.11.2006

By Jonathan Amos Evidence is emerging from Africa that colours were being used in a symbolic way perhaps 200,000 years ago, a UK scientist working in the region claims. Lawrence Barham has been studying tools and other artefacts left by ancient humans at a site in Zambia. He says the range of mineral pigments, or ochres, found there hints at the use of paint, perhaps to mark the body. If correct, it would push back the earliest known example of abstract thinking by at least 100,000 years. Being able to conceptualise - the ability to let one thing represent another - was a giant leap in human evolution. It was the mental activity that would eventually permit the development of sophisticated language and maths. Shells from Israel that were strung as beads into a necklace or bracelet are widely accepted to be the oldest unequivocal evidence for such behaviour in humans. But Dr Barham said it would be hard to accept that humans were not engaged in such activity much earlier in the archaeological record. "As an archaeologist I am interested to find out where colour symbolism first appears because for colour symbolism to work it must be attached to language," the Liverpool University researcher said. "Colour symbolism is an abstraction and we cannot work this abstraction without language; so this is a proxy for trying to find in the archaeological record real echoes for the emergence of language," Dr Barham told the British Association's Science Festival. (C)BBC

Keyword: Evolution
Link ID: 9323 - Posted: 09.11.2006

By BARNABY J. FEDER TAMARA KNIGHT remembers little of the summer of 2004 beyond a numbing despair that resisted 16 different antidepressant drugs. She dreaded a return to electroshock therapy, which she had tried periodically for years, because it brightened her mood for only a few weeks, at best, while progressively destroying her memory. “She was in as dark and low a place as you can ever imagine a person living,” said Don Knight, her husband. So Ms. Knight drove to a drugstore in her hometown of Columbus, Ga., bought two large bottles of extra-strength Excedrin and two boxes of sleeping pills. She said she swallowed as many of the pills as she could before she passed out. Katherine V. Coram, another depression sufferer with a history of attempted suicide, was in relatively better shape that same summer. She had managed to cling to a job at the National Archives in Washington, where an understanding boss gave her a light workload. But Ms. Coram felt defeated. Her three years in a clinical trial to see if an implanted nerve stimulator could control her illness had ended with hellish results. “I was hospitalized three times in the year after I got it for anxiety, panic and other problems — after having gone 15 years without hospitalization,” said Ms. Coram, who lives alone in Silver Spring, Md. “Once I even hit a stranger in a restaurant after I got mad. It was totally out of character for me.” Copyright 2006 The New York Times Company

Keyword: Depression
Link ID: 9322 - Posted: 06.24.2010

When you eat chicken, does it feel pointy or round? Is a week shaped like a tipped-over D with the days arranged counterclockwise? Does the note B taste like horseradish? Do you get confused about appointments because Tuesday and Thursday have the same color? Do you go to the wrong train station in New York City because Grand Central has the same color as the 42nd Street address of Penn Station? When you read a newspaper or listen to someone speaking do you see a rainbow of colors? If so, you might have synesthesia. Synesthesia is an anomalous blending of the senses in which the stimulation of one modality simultaneously produces sensation in a different modality. Synesthetes hear colors, feel sounds and taste shapes. What makes synesthesia different from drug-induced hallucinations is that synesthetic sensations are highly consistent: for particular synesthetes, the note F is always a reddish shade of rust, a 3 is always pink or truck is always blue. The estimated occurrence of synesthesia ranges from rarer than one in 20,000 to as prevalent as one in 200. Of the various manifestations of synesthesia, the most common involves seeing monochromatic letters, digits and words in unique colors—this is called grapheme-color synesthesia. One rather striking observation is that such synesthetes all seem to experience very different colors for the same graphemic cues. Different synesthetes may see 3 in yellow, pink or red. Such synesthetic colors are not elicited by meaning, because 2 may be orange but two is blue and 7 may be red but seven is green. Even more perplexing is that synesthetes typically report seeing both the color the character is printed in as well as their synesthetic color. For example, is both blue (real color) and light green (synesthetic color). © 1996-2006 Scientific American, Inc.

Keyword: Miscellaneous
Link ID: 9321 - Posted: 06.24.2010

Anticipating a gruesome or traumatic event makes it more vivid and deeply imprinted in the memory, a study says. Researchers found if people were aware something was going to happen, a key memory-forming part of the brain fired. The University of Wisconsin-Madison said the findings may have implications in the treatment of conditions such as post-traumatic stress disorder. The study, based on 36 people, is published in the Proceedings of the National Academy of Sciences journal. Researchers showed the volunteers symbols before exposing them to a series of gruesome images, such as pictures of mutilated bodies, while linked up to MRI scanners. The symbols were either neutral or signified that they were about to be shown something gruesome. Half an hour after being shown the images, the volunteers were quizzed about how well they remember them. Two weeks later, the volunteers were asked again. On both occasions, those who had previously been given an indication that gruesome pictures were going to be shown were more likely to remember them. After studying the MRI scans, researchers found two parts of the brain - the amygdala and hippocampus - were activated during the anticipation stage. Scientists think the amygdala is associated with the formation of emotional memories, while the hippocampus helps the brain form long-term recollections. (C)BBC

Keyword: Learning & Memory; Emotions
Link ID: 9320 - Posted: 09.09.2006

Bruce Bower Scientists for the first time have established that for a brief period after birth, baby monkeys imitate facial movements made by people and adult monkeys. This copycat capacity, until now observed only in human and chimpanzee infants, seems to have evolved in all these primates as a way to jump-start newborns' face-to-face communication with adults, say evolutionary biologist Pier F. Ferrari of the University of Parma in Italy and his colleagues. Between 3 and 7 days after birth, macaque babies smacked their lips and stuck out their tongues just as an experimenter did, the researchers report in the September PLoS Biology. Adult macaques make these facial gestures during friendly or cooperative interactions, such as mutual grooming. The baby monkeys stared impassively when experimenters opened and closed their mouths or right hands. A rotating, colored disk about the size of a face also elicited no reaction. Preliminary observations of free-ranging macaques by Ferrari's group further suggest that newborns mimic their mothers' lip smacking and tongue protrusion. "I think that [infant] imitation developed in species in which face-to-face communication predominates over other channels of communication," Ferrari says. Researchers have generally held that imitation in the service of social learning occurs only in people and apes. Ferrari's team questioned that assumption after the recent discovery in macaque brains of mirror neurons. ©2006 Science Service.

Keyword: Learning & Memory; Emotions
Link ID: 9319 - Posted: 06.24.2010

Helen Thomson Teenagers are more selfish than adults because they use a different part of their brain to make decisions compared to adults, new research suggests. Previous work has shown that when children reach puberty, there is an increase in connections between nerves in the brain. This occurs particularly in the area involved in decision-making and awareness of other people’s feelings, called the "mentalising network". Now Sarah-Jayne Blakemore, a cognitive neuroscientist from University College London, UK, has used functional magnetic resonance imaging (fMRI) to scan the brains of 19 adolescents (aged 11 to 17) and 11 adults (aged 21 to 37) whilst they were asked questions relating to decision-making. Questions such as: “You’re going to the cinema, where do you look for film times?” Blakemore found that teenagers rely on the rear part of the mentalising network to make their decisions, an area of the brain called the superior temporal sulcus. In contrast, adults use the front part, called the prefrontal cortex. The superior temporal sulcus is involved in processing very basic behavioural actions, whereas the prefrontal cortex is involved in more complex functions such as processing how decisions affect others. So the research implies that "teenagers are less able to understand the consequences of their actions", says Blakemore. © Copyright Reed Business Information Ltd.

Keyword: Development of the Brain
Link ID: 9318 - Posted: 06.24.2010

By Elli Leadbeater Although many people might not draw a duck very well, few would include four legs and eyebrows in their picture. But those who suffer from a common type of dementia confuse concepts such as "bird" and "dog", and will produce the strangest drawings. The area of the brain that stores meaning is damaged in these people. Researchers from the University of Manchester may have finally solved a 150-year-old debate by pinpointing where that area actually is. They think that a brain sector just underneath the ears, called the temporal pole, is responsible. Professor Matthew Lambon Ralph, of Manchester University said: "At the heart of communication is me getting a meaning from me to you. If you don't understand that meaning, then the middle part of all communication falls away." The researcher and his team had previously suspected the temporal pole was involved. Their suspicions were based on images which had shown that people with semantic dementia, who can struggle with even simple concepts such as "car" and "fork", have lost tissue from that area. But until now it was impossible to be sure, because these patients might also have other brain damage, too. By artificially slowing down the temporal pole's activities in volunteers with normal brains, the researchers have been able to show that it does play a part in storing meanings. The research team used a technique called transcranial magnetic stimulation, or TMS. This involves placing a magnetic coil on the side of the head, just above the temporal pole. The magnetic pulses exhaust the part of the brain underneath, so that for about 10 minutes it is too tired to work properly. (C)BBC

Keyword: Alzheimers
Link ID: 9317 - Posted: 09.08.2006

By Marc Kaufman The Drug Enforcement Administration yesterday overturned a two-year-old policy that many pain specialists said was limiting their ability to properly treat chronically ill patients in need of powerful, morphine-based painkillers. While defending its efforts to aggressively investigate doctors who officials conclude are writing painkiller prescriptions for no "legitimate medical purpose," the agency agreed with the protesting experts that it had gone too far in limiting how doctors prescribe the widely used medications. The unusual turnaround was welcomed by relieved doctors, who said it will help restore "balance" in government policy between the needs of pain patients and the effort to control prescription drug abuse and diversion. Specifically, the DEA proposed a formal rule that would allow doctors with patients who need a constant supply of morphine-based painkillers to write multiple prescriptions in a single office visit. Under the new rule, a doctor can write three 30-day prescriptions at a time -- two of them future-dated -- to be filled a month apart. Two years ago, the agency clamped down on the common practice of writing such multi-month prescriptions, which it said were probably illegal and were contributing to the growing abuse of prescription painkillers. © 2006 The Washington Post Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 9316 - Posted: 06.24.2010

How did our evolutionary ancestors make sense of their world? What strategies did they use, for example, to find food? Fossils do not preserve thoughts, so we have so far been unable to glean any insights into the cognitive structure of our ancestors. However, in a study recently published in Current Biology (September 5, 2006), researchers at the Max Planck Institute for Psycholinguistics and their colleagues at the Max Planck Institute for Evolutionary Anthropology were able to find answers to these questions using an alternative research method: comparative psychological research. In this way, they discovered that some of the strategies shaped by evolution are evidently masked very early on by the cognitive development process unique to humans. Being able to remember and relocate particular places where there is food is an asset to any species. There are two basic strategies for remembering the location of something: either remembering the features of the item (it was a tree, a stone, etc.), or knowing the spatial placement (left, right, middle, etc.). All animal species tested so far - from goldfish, pigeons and rats though to humans - seem to employ both strategies. However, if the type of recall task is designed so that the two strategies are in opposition, then some species (e.g. fish, rats and dogs) have a preference for locational strategies, while others (e.g. toads, chickens and children) favor those which use distinctive features. Until now, no studies had systematically investigated these preferences along the phylogenetic tree. Recently, however, Daniel Haun and his colleagues have carried out the first research of its kind into the cognitive preferences of a whole biological family, the hominids. They compared the five species of great apes - orangutans, gorillas, bonobos, chimpanzees and humans - to establish which cognitive strategies they prefer in order to uncover hidden characteristics.

Keyword: Learning & Memory; Evolution
Link ID: 9315 - Posted: 09.08.2006

By Mary Beckman Male chimpanzees, long considered very aggressive members of the great ape family, may have a caring side after all. A study conducted in Guinea reveals that high-ranking male chimps appear to adopt a protective role to get their group across big streets safely. Researchers know a lot about how monkeys travel in packs to protect the clan. Males often lead the way toward watering holes that may harbor predators, for example, and they bring up the rear on the way out. But not much is known about how their great ape cousins protect their gang from dangers. Although gorillas have a soft side--they'll care for orphans--adult male chimps will kill baby chimps. Can chimps put aside their aggression for the safety of the clan when it's on the move? To find out, psychologist James Anderson of the University of Stirling in the U.K. and colleagues traveled to Bossou, Guinea, and watched how 12 chimps, navigating from the forest to their foraging grounds, crossed two roads. One road is narrow and used primarily by pedestrians; the other is four times wider and carries trucks and other vehicles. The researchers found that the animals waited about half a minute before crossing the smaller road, while taking an average of 6 minutes before braving the big one. The authors argue that this represents a flexible response to different amounts of risk. © 2006 American Association for the Advancement of Science.

Keyword: Emotions; Evolution
Link ID: 9314 - Posted: 06.24.2010

The National Institute of Mental Health (NIMH), part of the National Institutes of Health (NIH), has launched three major clinical studies on autism at its research program on the NIH campus in Bethesda, Maryland. These studies are the first products of a new, integrated focus on autism generated in response to reported increases in autism prevalence and valid opportunities for progress. Initial studies will define the characteristics of different subtypes of autism spectrum disorders (ASD) (http://www.nimh.nih.gov/healthinformation/autismmenu.cfm) and explore possible new treatments. One study will define differences — both biological and behavioral — in autistic children with diverse developmental histories. Increasingly, scientists are considering the likelihood of “autisms,” that is, multiple disorders that comprise autism. These studies seek to better define the subtypes within autism. Children with regressive autism appear to develop normal language and social skills but then lose these with the onset of autism before age 3. Non-regressive autism, the more common form of the disorder, begins early in life, possibly before birth, with evidence of subtle deficits throughout development. Children with these two forms of autism will be compared with those who have other developmental disorders, including various forms of developmental delay, as well as children with typical development. In addition, researchers will study a subset of the children in this study to investigate environmental factors that may trigger symptoms of autism.

Keyword: Autism
Link ID: 9313 - Posted: 06.24.2010

Michael Hopkin Neuroscientists have reignited the debate over whether patients in a vegetative state are conscious of their surroundings, by claiming that a woman in such a 'waking coma' can respond to verbal commands. The researchers say that brain scans show that she can selectively think of performing certain actions, such as playing tennis, on request. The British-led research team made the discovery after examining the brain of a severely brain-damaged patient who had been in a vegetative state — defined as a lack of detectable consciousness — for five months. After years of studying the brains of vegetative patients, this is the first evidence, the researchers say, of awareness in such a patient, rather than simple automatic brain responses. The patient, a 23-year-old woman who was severely injured in a car accident in July 2005, had shown no outward signs of awareness. She had retained normal patterns of sleep and open-eyed 'wakefulness', report Adrian Owen, of the Medical Research Council Cognition and Brain Sciences Unit in Cambridge, UK, and his colleagues — but her open eyes could not focus or follow someone around a room. The team first compared scans of the patient's brain with those of 12 healthy volunteers in response to commands either to picture themselves playing a game of tennis or to imagine walking around their house. The two imagined activities produced markedly different patterns of brain activation when scanned using functional magnetic resonance imaging (fMRI), which highlights regions of brain activity. ©2006 Nature Publishing Group

Keyword: Brain imaging
Link ID: 9312 - Posted: 06.24.2010

A previously unrecognised trigger for autism may have been found, in the form of mutations that affects neuron development in a brain region important for learning and social interaction. Autism is around four times more common in boys than girls, which suggests that mutations on the X chromosome play a role, as boys lack a second X chromosome that could compensate for any genetic abnormality. Studies have identified several hundred gene candidates, but no conclusive links to a specific mutation. Now a 15-year-long international screening effort has identified two different mutations of the same X chromosome gene, which seem to be linked to autism in two unrelated families (Molecular Psychiatry, DOI: 10.1038/sj.mp.4001883). The gene encodes a protein called L10, a vital component of ribosomes - the structures that build proteins. L10 is most actively manufactured in the hippocampus, a brain region important in learning and memory as well as some social and emotional functions. Lead author Sabine Klauck of the Division of Molecular Genome Analysis at the German Cancer Research Centre in Heidelberg says the mutations are rare, and not present in their other patients. But they do reveal an important pathway by which different genetic defects could lead to different types of autism. © Copyright Reed Business Information Ltd.

Keyword: Autism; Genes & Behavior
Link ID: 9311 - Posted: 06.24.2010

Helen Thomson The part of the brain responsible for the way we understand words, meanings and concepts has been revealed as the anterior temporal lobe – a region just in front of the ears. In a novel experiment, neuroscientists pinpointed the exact region of the brain that is responsible for encoding semantic memory, which is disrupted in certain forms of dementia. Semantic dementia is the second most common form of dementia in under-65s and is associated with significant loss of brain tissue in the temporal lobe. Patients are able to generate speech fluently but lose their knowledge of objects, people and abstract concepts. For example, when shown a picture of a camel, they may understand that it is an animal but will not be able to give its name, and they lose the idea of associated concepts, such as deserts and palm trees. Matthew Lambon-Ralph and colleagues at the University of Manchester in the UK used transcranial magnetic stimulation (TMS) on 12 healthy volunteers in an attempt to detect which area of the brain is responsible for encoding this type of memory. © Copyright Reed Business Information Ltd.

Keyword: Learning & Memory
Link ID: 9310 - Posted: 06.24.2010

Women using some hormone replacement therapies may be putting their hearing at risk, US researchers have claimed. A study found women using HRT with oestrogen and progestogen had worse hearing than those using oestrogen-only HRT or no HRT at all. The University of Rochester team gave hearing tests to 124 post-menopausal women aged 60 to 84. But experts said the link, reported by Proceedings of the National Academy of Sciences, was "far from established". HRT is used by about one million middle-aged women in the UK to treat the symptoms of menopause, including mood swings and hot flushes. The majority of women use HRT containing both hormones, as oestrogen-only HRT is usually reserved for women who have had hysterectomies, as it increases womb cancer risk. HRT has come under close scrutiny in recent years. Research has suggested that HRT using a combination of the hormones oestrogen and progestogen may increase the risk of breast cancer. And some studies have also suggested a similar risk is associated with the oestrogen-only form. The treatment has also been linked to heart and dementia problems. The latest study found the group taking HRT with both hormones had poorer speech perception compared with the other groups. This problem was also present with background noise and in quiet surroundings, suggesting that problems occurred both in the inner ear and portions of the brain used for hearing. The report said it was not clear why the effect was found, but it did suggest progestogen may alter the levels of an acid known as GABA in the brainstem and ear auditory system. Researchers recommended more stringent testing of HRT medications to ensure they do not accelerate sensory losses that may impact upon quality of life and professional abilities. (C)BBC

Keyword: Hormones & Behavior; Hearing
Link ID: 9309 - Posted: 09.06.2006

By Dan Whipple Several cultures believe that the mind can be harnessed to control aspects of our physiology, such as ramping up the immune system to fight off a cold. Now, this belief has gotten a dose of scientific support from a study that suggests that the central nervous system can regulate pain and even reduce joint damage in arthritic rats. A team of researchers led by arthritis specialist Gary Firestein of the University of California, San Diego, investigated the influence of the central nervous system in rats with rheumatoid arthritis by blocking a compound made by the spinal cord. The compound, an enzyme called p38 MAP kinase, signals pain and inflammation in rheumatoid arthritis. When the researchers injected a drug into the rats' spines that blocks p38 MAP kinase, swelling in the animals' paws decreased markedly. In addition, rats injected with the drug didn’t respond to ankle pressure, demonstrating reduced pain. Damage to the joints from arthritis was decreased by 60% after spinal injection, compared to untreated animals, the researchers report online 4 September in PLoS Medicine. Firestein says the findings suggest that the central nervous system senses peripheral tissue inflammation, then activates the p38 pathway. Researchers have previously injected p38 MAP kinase inhibitors into arthritic tissues to control pain and inflammation in animals with some success, but the new work indicates that injecting it into the central nervous system may be more effective, he says. © 2006 American Association for the Advancement of Science.

Keyword: Pain & Touch
Link ID: 9308 - Posted: 06.24.2010

A type of protein crucial for the growth of brain cells during development appears to be equally important for the formation of long-term memories, according to researchers at UC Irvine. The findings could lead to a better understanding of, and treatments for, cognitive decline associated with normal aging and diseases such as Alzheimer’s. The findings appear in the early online edition of the Proceedings of the National Academy of Sciences. “This study presents strong evidence that a molecular process fundamental during development is retained in the adult and recycled in the service of memory formation,” said Thomas J. Carew, Donald Bren Professor and chair of UCI’s Department of Neurobiology and Behavior. “It is a striking example of how molecular rules employed in building a brain are often reused for different purposes throughout a lifetime.” The researchers have shown that proteins known as growth factors are as essential for the induction of long-term memory as they are for the development of the central nervous system. These growth factors, such as brain derived neurotrophic factor (BDNF), bind onto the brain cell through a specific type of receptor known as TrkB, much the same way a key fits into a lock. As an experimental strategy to determine the importance of BDNF-like growth factors in forming memories, the researchers used a “molecular trick” to keep the proteins from binding with the appropriate TrkB receptors. © Copyright 2002-2006 UC Regents

Keyword: Learning & Memory; Trophic Factors
Link ID: 9307 - Posted: 06.24.2010