Links for Keyword: Genes & Behavior

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BOSTON- Researchers at Dana-Farber Cancer Institute have compiled the first atlas showing the locations of crucial gene regulators, or switches that determine how different parts of the brain develop – and, in some cases, develop abnormally or malfunction. The scientists say the map will accelerate research on brain tumors and neurological diseases that result from mutations in these switch genes – called "transcription factors." When these genes are altered, the genes they control can go awry, causing abnormalities in the development or function of nerves and related structures. Although the gene regulators were pinpointed using mouse brains, the map applies to the human brain as well. "This is the first systematic mapping of all of the major brain areas that shows what regulatory genes are expressed in those specific locations," said Quifu Ma, PhD, of Dana-Farber's Cancer Biology Department. He is senior author of a paper appearing in today's online issue of the journal Science, along with Charles D. Stiles, PhD, also of Dana-Farber. Transcription factors are genes that control the expression, or activity, of "target" genes. These factors play a pivotal role in brain development by direction the formation of neurons and supporting cells called glia from uncommitted progenitor cells. Until now, brain transcription factors had not been systematically isolated and their locations within different parts of the brain pinned down.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 6617 - Posted: 06.24.2010

Female mice that are abnormally small due to gene "knockout" technology are also bad mothers whose poor parenting skills cause their young to die within a day or two of birth, scientists report this week in the on-line edition of the Proceedings of the National Academy of Sciences. Since Chawnshang Chang, Ph.D., cloned the gene for testicular orphan receptor 4 (TR4) 10 years ago, he and other scientists have tried to learn its function – scientists call it an "orphan" receptor because they don't know what protein links up with it. So a team led by Chang, director of George Whipple Laboratory for Cancer Research at the University of Rochester Medical Center, knocked out the gene in mice, then watched what happened. They found that many of the mice died before birth. Those that lived are markedly smaller than their normal counterparts: They're born far smaller and then make up some of the difference as they grow, but generally they are about 20 to 30 percent smaller by the time they reach adulthood. The miniature mice are not as fertile as normal mice, having only about half the offspring as other mice. Most visibly, the females have very bad parenting skills: They don't build nests, nurse their young, or tend to their offspring, which die within a day or two as a result.

Related chapters from BP7e: Chapter 5: Hormones and the Brain; Chapter 12: Sex: Evolutionary, Hormonal, and Neural Bases
Related chapters from MM:Chapter 8: Hormones and Sex; Chapter 8: Hormones and Sex
Link ID: 6255 - Posted: 06.24.2010

Honeybees can precisely regulate the temperature of their nest – and they do it thanks to genetically determined variations in their individual thermostats. The new research has revealed one of the few known benefits of the high genetic diversity found in honeybee colonies. Maintaining a nest temperature of between about 32C and 36C is vital during spring and summer, when eggs are developing and hatching. “If they don’t keep the nest at this temperature, the brood won’t develop properly,” says Julia Jones of the University of Sydney, Australia, who led the work. If the temperature drops too low, the worker bees huddle together around the brood to keep it warm. If it gets too high, they stand at the nest entrance and use their wings to fan out hot air. The new work shows that bees with different fathers start fanning at slightly different temperatures. This stops sudden colony-wide shifts between warming and cooling behaviours, and keeps the temperature in the nest more constant. “It’s been shown before that honeybees with different genotypes have different thresholds for certain things – for instance, they’re attracted to different concentrations of nectar," says Jones. "But this is the first time any benefit has been shown from different behaviour thresholds based on genotype in the bees.” © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 13: Homeostasis: Active Regulation of the Internal Environment
Related chapters from MM:Chapter 9: Homeostasis: Active Regulation of the Internal Environment
Link ID: 5706 - Posted: 06.24.2010

– Adrian Bird and Skirmantas Kriaucionis of the University of Edinburgh have discovered a novel form of the protein MeCP2. This alternate form, coined MeCP2 alpha, differs from the original only in the first 19 amino acids. Interestingly, Adrian Bird, Director of the Welcome Trust Centre for Cell Biology at Edinburgh University, found that MeCP2 alpha, is ten times more prevalent not only in the brain but also in other tissues. These findings are currently reported online in Nucleic Acids Research. Similar findings were reported yesterday in Nature Genetics online by Berge Minassian, a neurologist and scientist at Toronto's Hospital for Sick Children. Adrian Bird originally cloned the MECP2 gene in 1992 while in Vienna, Austria at the Institute for Molecular Pathology. In October of 1999 Huda Zoghbi of Baylor College of Medicine and the Howard Hughes Medical Institute announced that mutations in the MECP2 gene were the leading cause of Rett Syndrome (RTT). RTT is a severe neurological disorder diagnosed almost exclusively in girls. Children with RTT appear to develop normally until 6 to 18 months of age, when they enter a period of regression, losing speech and motor skills. Most develop repetitive hand movements, irregular breathing patterns, seizures and extreme motor control problems. RTT leaves its victims profoundly disabled, requiring maximum assistance with every aspect of daily living. There is no cure.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 5166 - Posted: 06.24.2010

– BETHESDA, MD – As the US population ages, there is an increasing effort to understand the underlying mechanisms that contribute to learning and memory. This effort could be of critical importance to scientists trying to decipher how the molecular genetic mechanisms of learning and memory are disrupted or impaired. The results of a new study provide evidence that individual differences in some cognitive functions may have a genetic basis. A New Study The authors of the study are Nelson Ruiz-Opazo, of the Section of Molecular Medicine, Boston University School of Medicine, Boston, MA, and John Tonkiss, from the Center for Behavioral Development and Mental Retardation, Boston University School of Medicine, Boston, MA. Their study, entitled "X-Linked Loci Influence Spatial Navigation Performance in Dahl Rats," now appears in the Articles in Press section of Physiological Genomics, one of one of 14 scientific journals published monthly by the American Physiological Society (APS) (www.the-aps.org).

Related chapters from BP7e: Chapter 18: Attention and Higher Cognition; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 14: Attention and Consciousness; Chapter 13: Memory, Learning, and Development
Link ID: 4919 - Posted: 06.24.2010

SACRAMENTO, Calif.) – A team of researchers, led by physicians at the UC Davis M.I.N.D Institute, have discovered a new, progressive neurodegenerative disorder that predominantly affects men over age 50 and results in tremors, balance problems and dementia that become increasingly more severe with age. A significant but currently unknown number of adults with these tremor and balance problems are being diagnosed as normal aging, Parkinson's disease, senile dementia and Alzheimer's disease when their condition may be accurately and easily identified with a standard DNA blood test ordered by their doctor. The discovery is published in the Jan. 28 issue of the Journal of the American Medical Association. Known as fragile X-associated tremor/ataxia syndrome, or FXTAS (pronounced fax-tass), the disorder affects older men who are carriers of a small mutation (premutation) in the same gene that causes fragile X syndrome, the most common cause of inherited mental retardation. Nearly 1 in 800 men in the general population carries this premutation in the fragile X gene, and UC Davis research suggests that as many as 30 percent of carriers -- roughly 1 in 3,000 men -- may develop FXTAS later in life.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 4871 - Posted: 06.24.2010

St. Louis, -- For some brain tumors, the key to success is not just what you know but who you know, according to researchers at Washington University School of Medicine in St. Louis. In trying to develop a mouse model of neurofibromatosis 1 (NF1), a genetic disorder that predisposes children to certain types of brain tumors, the team discovered that tumors only developed when all brain cells were genetically abnormal, not just the cell type that becomes cancerous. The study is featured on the cover of the Dec. 15 issue of the journal Cancer Research. "We are quite excited about this report as it represents the first model of this type of tumor," says principal investigator David H. Gutmann, M.D., Ph.D., the Donald O. Schnuck Family Professor of Neurology. "We've always assumed that cancer results from the loss of specific genes in a particular cell, but apparently that isn't always the case. Our findings suggest that as in real estate, location is everything – a permissive environment may be the key to whether a tumor cell becomes cancerous or just sits dormant for a person's entire life."

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 4696 - Posted: 06.24.2010

Discovery shows power of mouse genome to identify human genes for rare genetic diseases ANN ARBOR, MI – In a small town on Grand Cayman Island in the Caribbean, people are living with a serious neurological disorder, called Cayman ataxia, found nowhere else in the world. People born with this rare, inherited condition have poor muscle coordination, some degree of mental retardation, uncontrollable head and eye movements and difficulty speaking or walking. Now, in a discovery that reinforces the importance of the mouse to human genetics, scientists at the University of Michigan Medical School have discovered two mutations in a gene called ATCAY, which appear to be responsible for Cayman ataxia in humans and for similar neurological disorders in mice.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 4376 - Posted: 06.24.2010

When a plane arrives late to an airport, it affects more than just the frustrated passengers on the tardy plane – the ripple effects could throw the entire day’s timetable off schedule. Similarly, in a new study, North Carolina State University geneticists have found that changes to genes regulating olfactory behavior in the fruit fly Drosophila melanogaster, a popular insect model for genetics, have far greater implications than previously appreciated. The study is presented in a paper published in the Sept. 7 online edition of Nature Genetics. Dr. Robert Anholt, professor of zoology and genetics, director of NC State’s Keck Center for Behavioral Biology and the paper’s lead author, said that in the study of how genes affect behavior, the days of thinking about genes in a linear fashion are over.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 4235 - Posted: 06.24.2010

HONOLULU, HI – Researchers have recently discovered a progressive neurodegenerative condition -- resulting in tremor, balance problems, and dementia -- which may affect as many as one in 3,000 men. This condition has now been associated with the same gene that causes fragile X syndrome, the most common heritable form of mental retardation. Findings of this study are being presented at the American Academy of Neurology Annual Meeting in Honolulu, March 29-April 5, 2003. Remarkably, the same gene has been found to cause these two different and independent syndromes, affecting different groups of individuals. Fragile X syndrome is a developmental disorder beginning in childhood, while the newly identified neurological syndrome (Fragile X Associated Tremor/Ataxia Syndrome, or FXTAS) affects mainly male carriers who were not affected by fragile X syndrome retardation, and who displayed no symptoms prior to age 50. "We discovered that FXTAS-affected individuals have numerous inclusions, or spherical particles, in their brain cells," noted study author Paul Hagerman, MD, PhD, professor of Biological Chemistry at the University of California Davis School of Medicine. Through this study, the researchers are determining what is in the inclusions and why they form. "We believe this finding is an important clue as to the cause of the disorder, one that may ultimately help with development of therapies for both the tremor disorder and fragile X syndrome."

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 3644 - Posted: 06.24.2010

COLLEGE STATION, – Inside a drawer in Luis Rene Garcia's biology lab, tens of thousands of roundworms are bumping into one another, slithering together and breeding. For the tiny worms, known to science as C. elegans, it's all just another day on a laboratory petri dish. But somewhere in the writhing masses, Dr. Garcia suspects, lie clues to a mystery with large implications: Is some behavior hereditary? Garcia, an assistant professor of biology at Texas A&M University, is an expert in the sexual habits of C. elegans and the genes that apparently control the behaviors. Although the premise that heredity influences human behavior is controversial, it is more generally accepted in animals, Garcia says, especially when it involves base behaviors such as mating. He straddles the familiar nature-nurture debate, theorizing that genes set basic tendencies and the environment shapes the behaviors further. To begin testing his hypothesis, Garcia is deconstructing some of the most elemental of all behaviors in one of the world's simplest organisms.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 3573 - Posted: 06.24.2010

COLLEGE STATION – They behaved just like pigs. Or at least, that's what a study of cloned pigs found at Texas A&M University. The behavior of cloned pigs, produced last year at Texas A&M, were compared to pigs bred normally. The recent study was completed by master's of science student Greg Archer, under the supervision of Dr. Ted Friend, professor of applied ethology in the department of animal science. "We found the variation within a litter of clones to be as variable or greater (than the normal litters) at least 80 percent of the time for all the tests that we did," Archer said.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 3249 - Posted: 06.24.2010

Philadelphia, PA) –While type 1 Neurofibromatosis (NF1) is primarily known to cause tumors of the nervous system, scientists were puzzled as to why patients with NF1 are also prone to cardiovascular problems such as hypertension and congenital heart disease. Researchers from the University of Pennsylvania School of Medicine have solved this particular part of the puzzle by showing how the Nf1 gene – which is mutated in those suffering from Neurofibromatosis – is also essential in endothelial cells, the cells that make up blood vessels. Type 1 Neurofibromatosis affects many children, occurring in one in every 4,000 births. The researchers believe their findings may result in new therapeutics for NF1, as well as provide validation of an animal model for the disease. Their findings will appear online today in advance of publication in the January issue of the journal Nature Genetics.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 3145 - Posted: 06.24.2010

Most people find caffeine stimulating – Americans alone consume about 350 million cups of coffee daily. But some people find that it makes them anxious instead. A recently completed study sheds new light on the likely reason for this difference. Individuals who have two linked genetic variations are far more likely to end up biting their nails following a jolt of caffeine than those who don't, reported Harriet de Wit of the University of Chicago on Sunday, Dec. 8 at the annual meeting of the American College of Neuropsychopharmacology held in San Juan, Puerto Rico. "This is the first time that anyone has identified why people have different behavioral reactions to the same drug," said de Wit.

Related chapters from BP7e: Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology; Chapter 11: Emotions, Aggression, and Stress
Link ID: 3135 - Posted: 06.24.2010

Rehovot, Israel---How do 30,000 genes in our DNA work together to form a large part of who we are? How do one hundred billion neurons operate in our brain? The huge number of factors involved makes such complex networks hard to crack. Now, a study published in the October 25 issue of Science uncovers a strategy for finding the organizing principles of virtually any network – from neural networks to ecological food webs or the Internet. A team headed by Dr. Uri Alon, of the Weizmann Institute of Science's Molecular Cell Biology Department has found several such organizational patterns – which they call "network motifs" – underlying genetic, neural, technological, and food networks. The mathematical technique was first proposed by Alon earlier this year (published in Nature Genetics) and has now been shown to be applicable in a wide range of systems. In developing the technique, Alon surmised that patterns serving an important function in nature might recur more often than in randomized networks. This in mind, he devised an algorithm that enabled him to analyze the plentiful scientific findings examining key networks in some well-researched organisms. Alon noticed that some patterns in the networks were inexplicably more repetitive than they would be in randomized networks. This handful of patterns was singled out as a potential bundle of network motifs.

Related chapters from BP7e: Chapter 1: Biological Psychology: Scope and Outlook; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior; Chapter 13: Memory, Learning, and Development
Link ID: 2951 - Posted: 06.24.2010

– Two research teams have converged on a novel gene that appears to regulate key aspects of communication between nerve and muscle cells. Knowing the identity and function of these regulatory signals, which have remained largely mysterious until now, will allow researchers to better understand how the nervous system forges important connections during development. The two research teams – one led by Howard Hughes Medical Institute investigator Michael O' Connor and his colleagues -- reported the discovery and characterization of the gene in fruit flies in articles in the February 15, 2002, issue of Neuron. The other team, led by former HHMI investigator Corey Goodman, discovered the same gene via a different route. Both research teams identified the gene, wishful thinking (wit), by studying the larval neuromuscular junction (NMJ) in the fruit fly Drosophila. The Drosophila NMJ consists of 30 muscle fibers that are attached to 35 neurons. The well-characterized system is a prime model for exploring how muscle growth triggers the growth of its innervating motor neurons that drive muscle contraction.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 1555 - Posted: 06.24.2010

By JUDITH SHULEVITZ How is a church like a can opener? Among the pleasures of using evolutionary logic to think about matters nonbiological, one is getting to ask questions like that. The evolutionary take on a cultural fact like religion or warfare can cut through the fog of judgment and show how a social institution solves some mechanical problem of human co-existence. What function did intergroup violence serve? What are gods good for? Nicholas Wade’s book “The Faith Instinct” is at its best when putting us through such exercises and sidelining the by-now tiresome debates about religion as a force for good or evil. According to Wade, a New York Times science writer, religions are machines for manufacturing social solidarity. They bind us into groups. Long ago, codes requiring altruistic behavior, and the gods who enforced them, helped human society expand from families to bands of people who were not necessarily related. We didn’t become religious creatures because we became social; we became social creatures because we became religious. Or, to put it in Darwinian terms, being willing to live and die for their coreligionists gave our ancestors an advantage in the struggle for resources. Wade holds that natural selection can operate on groups, not just on individuals, a contentious position among evolutionary thinkers. He does not see religion as what Stephen Jay Gould and Richard Lewontin called a spandrel — a happy side effect of evolution (or, if you’re a dyspeptic atheist, an unhappy one). He does not agree with the cognitive anthropologist Pascal Boyer that religion is a byproduct of our overactive brains and their need to attribute meaning and intention to a random world. He doesn’t perceive religious ideas as memes — that is to say, the objects of a strictly cultural or mental process of evolution. He thinks we have a God gene. Copyright 2009 The New York Times Company

Related chapters from BP7e: Chapter 6: Evolution of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 0: ; Chapter 11: Emotions, Aggression, and Stress
Link ID: 13607 - Posted: 06.24.2010

By Emily Anthes We take it for granted that certain aspects of our social behavior—whether we chat easily with strangers at a party, for instance, or prefer to be a wallflower—are influenced by genetics. But now researchers at the University of California, San Diego, and Harvard University have shown that genes have a much broader sway, affecting the kinds of social networks people form and the positions they occupy in them. James Fowler, a political scientist at U.C.S.D., and his colleagues studied the social networks of 1,110 adolescent fraternal and identical twins. They found that three aspects of the twins’ social networks appeared to be shaped by genetics. How many times each teen was named by others as a friend and how likely each youth’s friends were to know one another were both approximately 50 percent related to genetic factors. Whether a teen was located at the center of a network or toward the edge was about 30 percent genetic. “We have innate characteristics that give us a tendency to gravitate toward one part of a network,” Fowler explains. “We vary in the tendency with which we’ll attract people as friends, and we vary in our tendency to introduce our friends to one another.” The genetic foundation uncovered in the study, he posits, is probably a broad combination of genes that are mostly linked to personality traits such as humor, generosity or extroversion. © 1996-2009 Scientific American Inc.

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 11: Emotions, Aggression, and Stress
Link ID: 13037 - Posted: 06.24.2010

By Tina Hesman Saey Whether you like it or not, you’re a little different. If it makes you feel any better, so is everybody else. In fact, everybody is far more different than anybody had imagined. Scientists are only beginning to discover just how different humans are from each other at the genetic level and what those personal genetic attributes mean for health, history and the human evolutionary future. It’s true that people are 99.9 percent alike, if only minor spelling variations in the genetic instruction book are taken into account. In each person, about one in every 1,000 DNA bases — the chemical letters of the genetic alphabet — differs from the generic human construction and operating manual. So, on average, one person will differ from another at about 3 million of the 3 billion letters in the human genome. Researchers have recently mapped many of these single letter variations, called single 
nucleotide polymorphisms or SNPs, looking for variants that might play a role in complex diseases such as heart disease, diabetes and high blood pressure (SN: 6/21/08, p. 20). So far, SNPs have been associated with many diseases, but SNPs can also be protective. And those little spelling differences may contain information about a person’s geographic ancestry — just as whether people write color or colour is a clue about whether they hail from the United States or Great Britain. © Society for Science & the Public 2000 - 2009

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior; Chapter 16: Psychopathology: Biological Basis of Behavior Disorders
Related chapters from MM:Chapter 13: Memory, Learning, and Development; Chapter 12: Psychopathology: Biological Basis of Behavioral Disorders
Link ID: 12744 - Posted: 06.24.2010

By Tina Hesman Saey Tattoos on the skin can say a lot about person. On a deeper level, chemical tattoos on a person’s DNA are just as distinctive and individual — and say far more about a person’s life history. A pair of reports published online January 18 in Nature Genetics show just how important one type of DNA tattoo, called methylation, can be. Researchers at Johns Hopkins University report the unexpected finding that most DNA methylation — a chemical alteration that turns off genes — occurs most often near, but not precisely within, the DNA regions on which scientists have typically focused their studies. The other report, from researchers at the Universityof Toronto and collaborators, suggests that identical twins owe their similarity not only to having the same genetic make-up, but also to certain methylation patterns established in the fertilized egg. Methylation is just one of many epigenetic signals — chemical changes to DNA and its associated proteins — that modify gene activity without altering the genetic information in the genes. Methylation and other epigenetic signals help guide stem cells as they develop into other type of cells. Scientists have long suspected that mishandling methylation and other epigenetic flags could lead to cancer. The Johns Hopkins group has now shown that DNA methylation is more common at what they call “CpG island shores” instead of at the CpG islands that most researchers have been studying. CpG islands are short stretches of DNA rich in the bases cytosine and guanine, also known as C and G in the genetic alphabet. (Adenine (A) and thymine (T) are the other DNA bases.) CpG islands are located near the start site of genes and help control a gene’s activity. Planting a chemical flag called a methyl group on an island declares the gene off-limits, blocking activity. © Society for Science & the Public 2000 - 2009

Related chapters from BP7e: Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 13: Memory, Learning, and Development
Link ID: 12457 - Posted: 06.24.2010