Biosingularity

Two mice. One weighs 20 grams and has brown fur. The other is a hefty 60 grams with yellow fur and is prone to diabetes and cancer. They’re identical twins, with identical DNA

So what accounts for the differences?

It turns out that their varying traits are controlled by a mediator between nature and nurture known as epigenetics. A group of molecules that sit atop our DNA, the epigenome (which means “above the genome”) tells genes when to turn on and off. Duke University’s Randy Jirtle made one of the mice brown and one yellow by altering their epigenetics in utero through diet. The mother of the brown, thin mouse was given a dietary supplement of folic acid, vitamin B12 and other nutrients while pregnant, and the mother of the obese mouse was not. (Though the mice had different mothers, they’re genetically identical as a result of inbreeding.) The supplement “turned off” the agouti gene, which gives mice yellow coats and insatiable appetite

via Epigenetics research takes aim at cancer, Alzheimer’s, autism, other illnesses – washingtonpost.com.

Scientists have unlocked the entire genetic code of two of the most common cancers – skin and lung – a move they say could revolutionise cancer care.

Not only will the cancer maps pave the way for blood tests to spot tumours far earlier, they will also yield new drug targets, says the Wellcome Trust team.

Scientists around the globe are now working to catalogue all the genes that go wrong in many types of human cancer.

The UK is looking at breast cancer, Japan at liver and India at mouth.

China is studying stomach cancer, and the US is looking at cancers of the brain, ovary and pancreas.

via BBC News – Scientists crack ‘entire genetic code’ of cancer.

Taking a hint from natural antibiotics, a startup spun out of Stanford University is developing a way to chemically alter existing drugs to dramatically improve their half-life

By sequestering the drugs within cells, the researchers hope to protect them from the bodys efforts to destroy them. So far, the company has developed long-lasting versions of a protease inhibitor to fight HIV, as well as the antibiotic carbapenem. Amplyx is now developing new versions of a number of drugs that fight infection, and aims to test them in clinical trials within the next two years.

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Hiding drugs: In this human blood smear, a modified protease inhibitor shown in green is sequestered inside a white blood cell. The cell’s DNA is shown in blue. The drug slowly leaches out into the plasma, greatly extending the drug’s half-life.Credit: Paul MerrinakResearchers at Amplyx Pharmaceuticals decorate drug compounds with molecules designed to bind to specific proteins within cells, as well as binding to the drugs treatment target.

via Technology Review: Making Drugs Survive Longer in Blood.

Since the 1950s, researchers have been trying to mimic the abilities of red blood cells. These flexible discs carry oxygen throughout the body, squeezing through the smallest capillaries to do so. But the physical characteristics of red blood cells, including their doubly concave shape, have made them difficult to copy with precision.

In research published Monday in the Proceedings of the National Academy of Sciences, a group specializing in drug delivery has found a way to create biodegradable, biocompatible particles with the size, shape, and flexibility of red blood cells. The group believes these artificial cells might be particularly effective not just for carrying oxygen but also as therapeutic and imaging agents.

via Technology Review: Artificial Red Blood Cells for Drug Delivery.

Every cup of coffee a person drinks per day may lower the risk of diabetes by 7%.

A new review of research on the link between lifestyle factors, like coffee and tea consumption, and diabetes risk suggests that drinking regular or decaffeinated coffee and tea all lower the risk of type 2 diabetes.

via Coffee, Tea May Stall Diabetes.

Ever since he first discovered the lifespan-extending effects of proteins called sirtuins 15 years ago, MIT Professor Leonard Guarente has been accumulating evidence to demonstrate a link between sirtuins and the effects of calorie restriction on lifespan.

For decades, it has been known that cutting normal calorie consumption by 30 to 40 percent can boost lifespan and improve overall health in animals such as worms and mice. Guarente believes that those effects are controlled by sirtuins — proteins that keep cells alive and healthy in the face of stress by coordinating a variety of hormonal networks, regulatory proteins and other genes.

In his latest work, published yesterday in the journal Genes and Development, Guarente adds to his case by reporting that sirtuins bring about the effects of calorie restriction on a brain system, known as the somatotropic signaling axis, that controls growth and influences lifespan length.

via New evidence links sirtuins and life extension.

Unlike most researchers, the engineers at ImThera Medical just might consider it a compliment if someone called their product a “snooze.” The experimental device is designed to treat sleep apnea, a breathing disorder that can disrupt sleep and trigger serious complications, including an increased risk for heart disease and stroke, as well as daytime sleepiness so severe that sufferers often fall asleep at the wheel. The implant, which wraps around a nerve connected to the tongue, is now being tested in a small clinical trial in Europe.

via Technology Review: A Stimulating Treatment for Sleep Apnea.

gene which is essential for stem cells’ capabilities to become any cell type has been identified by researchers at the Hebrew University of Jerusalem and the University of California, San Francisco.

The discovery represents a further step in the ever-expanding field of understanding the ways in which stem cells develop into specific cells, a necessary prelude towards the use of stem cell therapy as a means to reverse the consequences of disease and disability. Read the rest of this entry »

Scientists have resolved a question about how a popular class of drugs used to treat schizophrenia works using biosensors that reveal previously hidden components of chemical communication in the brain.

Cells called CNiFERs (pronounced "sniffers") change color to reveal specific kinds of neural messages. Credit: Kleinfeld Lab, UC San Diego

Read the rest of this entry »

A previously incurable blood disorder – sickle-cell disease – has been successfully treated in 9 of 10 adults who received stem cells transplanted from tissue-matched siblings.

via Stem cell transplants treat ‘incurable’ blood disorder – health – 10 December 2009 – New Scientist.

Researchers at Yale have demonstrated a device that uses a magnetic liquid to separate blood cells based on their size and shape in just minutes.The device applies a magnetic field to a liquid containing magnetic nanoparticles. The nanoparticles create waves that carry cells along depending on their size, shape and mechanical properties. The researchers, led by electrical engineering professor Hur Koser, hope to develop a cheap alternative to cell-sorting techniques that are time-consuming and sometimes require expensive labeling.

via Technology Review: Blogs: TR Editors blog: Magnetic Liquid Separates Blood Cells.

A team of Princeton University scientists has produced a systematic listing of the ways a particular cancerous cell has “gone wrong,” giving researchers a powerful tool that eventually could make possible new, more targeted therapies for patients.

Read the rest of this entry »

What would happen if some soft tissue cells in your body randomly got the message to transform into stiff bone cells? Patients born with a disease called fibrodysplasia ossificans progressiva (FOP) are locked into this fate, often becoming severely disabled before adulthood.

The disease first manifests itself at birth, when a baby appears normal but has bent big toes. By early childhood, however, some of the body’s connective tissues—including muscles, ligaments and tendons—have begun ossifying into skeletal bone, locking the joints and distorting posture and movement. Some bone formation appears to be spontaneous, while some can be brought on by trauma from surgery or even a mild impact.

via How Can a Genetic Mutation Cause Muscle to Turn into Bone?: Scientific American.

If youve been diagnosed with breast cancer, you may want to cut down on alcoholic beverages.Thats the suggestion of researchers who found that cancer is 34% more likely to come back in breast cancer survivors who drink more than three drinks a week, compared with those who abstain or drink less.Drinking more than three drinks a week also raised the risk of dying from breast cancer by 51%, says Marilyn L. Kwan, PhD, a staff scientist at Kaiser Permanente in Oakland, Calif.

via Alcohol Ups Risk of Breast Cancer Recurrence.

Scientists at New York University report they have developed a drug-free, noninvasive way to temporarily block the return of fearful memories in people.

The technique, the researchers contend, could eventually change the way scientists view how the brain’s memory storage process works and perhaps even lead to new ways to treat anxiety disorders, including posttraumatic stress disorder.

Researcher Daniela Schiller, PhD, and colleagues at NYU say in a new study published in the journal Nature that they’ve been able to reshape memories. The process involves resurrecting unpleasant memories and creating a window of opportunity for reshaping the fears, a period called “reconsolidation.”

via Drug-Free Method of Blocking Fear Memories.

Scientists have discovered a new type of stem cell in the skin that acts surprisingly like certain stem cells found in embryos: both can generate fat, bone, cartilage, and even nerve cells. These newly-described dermal stem cells may one day prove useful for treating neurological disorders and persistent wounds, such as diabetic ulcers, says Freda Miller, an HHMI international research scholar. Read the rest of this entry »

Giving women more of the male hormone testosterone can turn them into fairer and more amiable game players, according to tests.A single dose of testosterone was enough to have this effect, European scientists found, but only if the woman was oblivious to the treatment.If she realised she had received the hormone and not a dummy drug, she turned to greed and selfishness.

The work in Nature magazine suggests the mind can win over hormones.Testosterone induces anti-social behaviour in humans, but only because of our own prejudices about its effect rather than its biological activity, suggest the authors.

They believe the same is true in men, although they only studied women.

via BBC News – Testosterone link to aggression all in the mind.

Besides treating depression, the antidepressant Paxil may affect personality traits in positive ways, a new study suggests.

Researchers say Paxil and likely other antidepressants in the class of drugs called selective serotonin reuptake inhibitors (SSRIs) may improve higher levels of neuroticism and lower levels of extraversion that are commonly seen with depression.

Neuroticism is characterized as being inclined to have negative emotions such as anxiety, hostility, self-consciousness, impulsivity, and sensitivity to stress.

Extraversion refers to being inclined to have positive emotions,  assertiveness, and gregariousness.

via Antidepressant Paxil Also May Affect Personality Traits.

Drinking coffee regularly may help lower the risk of advanced prostate cancer, a study shows.

The study, presented this week at a conference of the American Association for Cancer Research in Houston, shows men who drank the most coffee were nearly 60% less likely to develop advanced prostate cancer than non-coffee drinkers.

Researchers say it's too early to start recommending that men start drinking coffee to help prevent prostate cancer, but the results are encouraging.

via Coffee May Cut Risk of Prostate Cancer.

Moderate intake of soy foods by breast cancer survivors appears to be not only safe but beneficial, according to a new study.Women who had a higher soy intake had a lower mortality and lower risk of relapse [than women with a low intake],” says researcher Xiao Ou Shu, MD, PhD, professor of medicine at Vanderbilt University Medical Center in Nashville, Tenn.Previous research has yielded conflicting findings, with some studies finding that soy foods reduce breast cancer risk but others finding that genistein, an estrogen-like compound known as an isoflavone in soy, helps breast cancer cells grow in the lab and promotes tumor growth in animals.

via Soy Appears Safe for Breast Cancer Survivors.

Healthy levels of vitamin D may help patients with a certain type of non-Hodgkin's lymphoma live longer.

Researchers at the Mayo Clinic have discovered that patients with diffuse large B-cell lymphoma (DLBCL) and low vitamin D levels are two times more likely to die from the cancer than patients with optimal levels. Deficient vitamin D levels also increased the chances of cancer progression.

via Vitamin D May Boost Lymphoma Survival.

An experimental drug developed by Danish startup Santaris effectively controls the hepatitis C virus in chimpanzees without creating drug-resistant forms of the virus–a major advantage over other compounds in clinical development. The compound, a synthetic nucleic acid that binds to a microRNA molecule required for viral reproduction, is now in early-stage clinical trials. It is the first microRNA-targeting drug to be tested in humans.

via Technology Review: Hepatitis C Drug Targets RNA.

A new study of the Max Planck Institute for Biology of Ageing could help to understand the positive effect of dietary restriction on healthy ageing. Previous evidence from different organisms (fruit flies and mice) have shown that dietary restriction increases longevity, but with a potential negative side effect of diminished fertility. So the female fruit fly reproduces less frequently with a reduced litter size on a low calorie diet, but its reproductive span lasts longer. This is the result of an evolutionary trait, as scientists believe: essential nutrients are diverted towards survival instead of reproduction. (Nature, December 3, 2009) Read the rest of this entry »

The body is a battle zone. Cells constantly compete with one another for space and dominance. Though the manner in which some cells win this competition is well known to be the survival of the fittest, how stem cells duke it out for space and survival is not as clear. A study on fruit flies published in the October 2 issue of Science by Johns Hopkins researchers describes how stem cells win this battle by literally sticking around. Read the rest of this entry »

Researchers from Yale University and Mirna Therapeutics, Inc., reversed the growth of lung tumors in mice using a naturally occurring tumor suppressor microRNA. The study reveals that a tiny bit of RNA may one day play a big role in cancer treatment, and provides hope for future patients battling one of the most prevalent and difficult to treat cancers. Read the rest of this entry »

The electroencephalogram (EEG) has been widely used in research and medicine for more than eighty years. The ability to measure the electric activity in the brain by means of electrodes on the head is a handy tool to study brain functions as it is noninvasive and easy to apply. However, the interpretation of the EEG signals remains difficult. The main reason for this is that the exact relationship between the activities generated in the brain to that measured on the scalp is unclear. Read the rest of this entry »

In the first study to demonstrate a clear positive association between adolescent fitness and adult cognitive performance, Nancy Pedersen of the University of Southern California and colleagues in Sweden find that better cardiovascular health among teenage boys correlates to higher scores on a range of intelligence tests – and more education and income later in life. Read the rest of this entry »

A desktop instrument recently approved by the U.S. Food and Drug Administration might finally bring pharmacogenomic testing–the use of a patients genetic information for drug prescription decisions–to the mainstream. The device, made by Nanosphere, a startup based in Northbrook, IL, can, in a matter of hours, detect genetic variations in blood that modulate the effectiveness of some drugs. Dubbed Verigene, the technology employs a combination of microfluidics and nanotechnology, housed in a single plastic cartridge, to pull DNA from a blood sample and then screen it for the relevant sequences.

via Technology Review: Gene-Testing Machine for Doctors.

Previous studies have shown a link between low vitamin D status and heart disease. Now a new study shows that patients with high blood pressure who possess a gene variant that affects an enzyme critical to normal vitamin D activation are twice as likely as those without the variant to have congestive heart failure. Read the rest of this entry »

Scientists have long known that the human immune system has a method for detecting and destroying precancerous cells. But finding the cells behind this defense mechanism in order to study and perhaps even mimic them has proved quite the challenge. Since the malignant precancerous cells are eradicated before we even know they exist, identifying the cells that killed them seemed nearly impossible. Now European researchers have built a microfluidic biosensor that traps single immune cells together with single tumor cells, allowing the researchers to pick the most potent of these cancer killers out of a crowded field.

via Technology Review: Identifying Anticancer Immune Cells.

Can stem cells safely repair heart attack damage? Yes, a clinical trial suggests.Bone marrow stem cells are supposed to home in on damaged parts of the heart. Once there, they send out signals that help the body repair the injury. Theres also evidence, from animal studies, that the stem cells themselves engraft to the heart and help repopulate dead cells with new, living cells.Now theres evidence from actual patients who suffered heart attacks.

via Stem Cells Repair Heart Attack Damage.

Nanoparticles that deliver two or more drugs simultaneously can significantly shrink pancreatic cancer tumors and also reduce its spread, say researchers at Massachusetts General Hospital. Tayyaba Hasan, who is also a professor of dermatology at Harvard Medical School, led the development and testing of two “nanocells.” These nanocells combine light-based therapy with molecules that inhibit the growth of cancer cells or of the blood vessels that feed them.

Though the particles have only been studied in mice so far, the cancer-research community is excited. Pancreatic cancer remains one of the deadliest and hardest cancers to treat; mortality rates have changed very little in the last 30 years. After diagnosis, patients tend to live only six months, and less than 5 percent survive for five years. “In terms of a patient population, there is very little we can do for them once we find the cancer,” says Craig Thompson, director of the Abramson Cancer Center at the University of Pennsylvania.

via Technology Review: Big Hope for Tiny Particles.

A healthy body may be the first step to achieving a healthy mind and appetite for learning.

A large new study links cardiovascular fitness in early adulthood to increased intelligence, better performance on cognitive tests, and higher educational achievement later in life.

Researchers say the results suggest that promoting physical and cardiovascular fitness as a public health strategy could maximize educational achievement as well as prevent disease at the societal level.

via Cardiovascular Fitness May Sharpen Mind.

Researchers are now one step closer to being able to use skin tissue derived from stem cells for the treatment of burn victims, according to a study published November 21 in The Lancet.

By tweaking the way the cells are grown in a Petri dish, a team of scientists at the Institute for Stem Cell Therapy and Exploration of Monogenic Diseases near Paris, France, was able to coax human embryonic stem cells into becoming multilayered skin tissue. The group also grafted the human stem cell-derived skin onto the backs of five mice. The foreign tissue grew well for at least 12 weeks, suggesting that it could at least be a safe temporary solution until skin tissue from a patient's body, aka autologous graft tissue, is ready.

via Observations: Stem Cells Could Offer New Source for Skin Grafts.

Scientists at the California Institute of Technology (Caltech) have uncovered evidence of a primitive emotion-like behavior in the fruit fly, Drosophila melanogaster.

Their findings, which may be relevant to the relationship between the neurotransmitter dopamine and attention deficit hyperactivity disorder (ADHD), are described in the December issue of the journal Neuron.

The Drosophila brain contains only about 20,000 neurons and has long been considered a powerful system with which to study the genetic basis of behaviors such as learning and courtship, as well as memory and circadian rhythms. What hasn’t been clear is whether the Drosophilabrain also could be used to study the genetic basis of “emotional” behaviors. Read the rest of this entry »

Ghrelin, a hormone produced in the stomach, may be used to boost resistance to, or slow, the development of Parkinson’s disease, Yale School of Medicine researchers report in a study published in a recent issue of the Journal of Neuroscience. Read the rest of this entry »

Patients should avoid using the stomach acid reducer Prilosec/Prilosec OTC (omeprazole) with the anti-clotting drug Plavix (clopidogrel), the U.S. Food and Drug Administration warned on Nov. 17.

New data suggest that when patients take both Prilosec and Plavix, Plavix’s ability to block platelet aggregation (anti-clotting effect) may be reduced by about half.

“Both of these drugs, when used properly, provide significant benefits to patients.” said Mary Ross Southworth, Pharm.D., of the Division of Cardiovascular and Renal Products in the FDA’s Center for Drug Evaluation and Research. “However, patients at risk for heart attacks or strokes who use Plavix to prevent platelet aggregation will not get the full effect of this medicine if they are also taking Prilosec.”

Plavix is used to prevent blood clots that could lead to heart attacks or strokes in at-risk patients. Omeprazole, the active ingredient of Prilosec and Prilosec OTC, is a proton pump inhibitor (PPI) used to reduce the production of stomach acid and prevent stomach irritation.

via FDA Announces New Warning on Plavix: Avoid Use with Prilosec/Prilosec OTC.

Last year, researchers at the Rush University Medical Center in Chicago showed that human cells in culture could synchronize their internal chemical processes even though they were mechanically, chemically, and electrically isolated from one another. The cells, it seemed, were communicating through the exchange of photons.Various other groups have shown similar effects. Many cells seems to produce optical and UV photons at about 10 photons per square cm/s, a rate that cannot be explained by ordinary thermodynamic emissions. Other evidence indicates that this form of optical communication can increase the rate of mitosis in cells by up to 50 percent.So how do they do it? Today Sergei Mayburov at the Lebedev Institute of Physics in Moscow puts forward the idea that optical communication is a natural process in many cells that can be explained by the way we already know many cells to function.

via Technology Review: Blogs: arXiv blog: The Emerging Field of Biophotonic Communication.

On the skin’s surface, bacteria are abundant, diverse and constant, but inflammation is undesirable. Research at the University of California, San Diego School of Medicine now shows that the normal bacteria living on the skin surface trigger a pathway that prevents excessive inflammation after injury. Read the rest of this entry »

Whitehead researchers have developed a new type of genetic screen for human cells to pinpoint specific genes and proteins used by pathogens, according to their paper in Science.

In most human cell cultures genes are present in two copies: one inherited from the father and one from the mother. Gene inactivation by mutation is therefore inefficient because when one copy is inactivated, the second copy usually remains active and takes over.

In the rare human cell line used for this genetic screen, the cells have only one copy of each chromosome, except for chromosome 8, which has two copies. Because this cell line has only one copy of almost all of the chromosomes, it is ideal for efficiently making knockout human cells. Credit: Science/AAAS

Read the rest of this entry »

What are the bare essentials of life, the indispensable ingredients required to produce a cell that can survive on its own? Can we describe the molecular anatomy of a cell, and understand how an entire organism functions as a system?  In three papers published back-to-back today in Science, they provide the first comprehensive picture of a minimal cell, based on an extensive quantitative study of the biology of the bacterium that causes atypical pneumonia, Mycoplasma pneumoniae. The study uncovers fascinating novelties relevant to bacterial biology and shows that even the simplest of cells is more complex than expected.

This image represents the integration of genomic, metabolic, proteomic, structural and cellular information about Mycoplasma pnemoniae in this project: one layer of an Electron Tomography scan of a bottle-shaped M. pneumoniae cell (grey) is overlaid with a schematic representation of this bacterium's metabolism, comprising 189 enzymatic reactions, where blue indicates interactions between proteins encoded in genes from the same functional unit. Apart from these expected interactions, the scientists found that, surprisingly, many proteins are multifunctional. For instance, there were various unexpected physical interactions (yellow lines) between proteins and the subunits that form the ribosome, which is depicted as an Electron microscopy image (yellow).Credit: Takuji Yamada /EMBL

Read the rest of this entry »

Viruses multiply incredibly quickly once they've infected their victim–so fast that antiviral medications such as Tamiflu are only effective if given during the first few days of an infection. After that, the viral load is just too high for a single drug to fight off. But researchers are working on a treatment for the H1N1 virus (or swine flu) that uses a different approach. Rather than disabling the virus with a drug, they're creating a vaccine that can activate and steer a patient's own immune cells to attack the invader

via Technology Review: Arming the Immune System against H1N1.

By modifying a single gene, scientists have made Hobbie-J the smartest rat in the world, a new study says.

A similar gene tweak might boost human brainpower too, but scientists warn that there is such a thing as being too smart for your own good

For years scientifically smartened rats have skittered through movies and books such as Flowers for Algernon and The Secret of NIMH. But Hobbie-J is anything but fiction.

The lab rat can remember objects three times longer than her smartest kin, the study says. Thanks largely to this memory boost, she's also much better at solving complex tasks, such as traveling through mazes using only partial clues to find rewards—a key method for measuring rat intelligence.

via Rat Made Supersmart — Similar Boost Unsafe in Humans?.

Researchers have demonstrated a tiny chip based on silicon that could be used to diagnose dozens of diseases.

A tiny drop of blood is drawn through the chip, where disease markers are caught and show up under light.

The device uses the tendency of a fluid to travel through small channels under its own force, instead of using pumps.

The design is simpler, requires less blood be taken, and works more quickly than existing “lab on a chip” designs, the team report in Lab on a Chip.

via BBC News : Tiny chip could diagnose disease.

More than half a million people in the U.S. have died from HIV infection, and more than a million currently live with the virus, but a relative handful of people infected with HIV never get treatment for it and never get sick from it. The immune systems of this small population—perhaps 50,000 Americans—somehow control the virus for long periods of time. Of course, there is typically a bell curve of response to any disease, but figuring out how these people control the virus is one of the most vexing mysteries of the AIDS pandemic. Solving it might unlock new ways to prevent and treat HIV infection, and now several research teams are going after the answer.

via Researchers Try to Solve the Mystery of HIV Carriers Who Don’t Contract AIDS: Scientific American.

Drugs that boost the chemical messenger norepinephrine in the brain have been shown to alleviate cognitive problems in mice engineered to mirror Down syndrome. The findings, published today in the journal Science Translational Medicine, suggest a new approach to treating the disorder. Several existing drugs can boost the chemical or mimic its effects, though none have yet been tested in patients with Down syndrome.

via Technology Review: Potential Treatment for Down Syndrome.

Next time you're stuck in traffic, try deep breathing exercises instead of honking your horn. It could save your life.

Researchers found that people who have a positive attitude during stressful events are 22% less likely to have a fatal or nonfatal heart attack than those who have negative attitudes.

via Positive Attitude Staves Off Heart Disease.

There is new evidence that folic acid, taken in large doses, may promote some cancers.

Heart patients in Norway who took folic acid and vitamin B12 supplements were found to have a slightly increased risk for cancer and death from all causes, compared to heart patients who did not take the supplements in a study published in TheJournal of the American Medical Association.

via Folic Acid, B12 May Increase Cancer Risk.

People constantly make complex decisions, from the more mundane—which restaurant to go to for dinner or which movie to go see—to the more profound—whether to have kids or not. Now, a new study published online on November 12th in Current Biology, a Cell Press publication, confirms an important role for the brain chemical dopamine in how people make such life choices, by influencing our expectations of the pleasure associated with their outcomes. Read the rest of this entry »

Short-term memory may depend in a surprising way on the ability of newly formed neurons to erase older connections. That’s the conclusion of a report in the November 13th issue of the journal Cell, a Cell Press publication, that provides some of the first evidence in mice and rats that new neurons sprouted in the hippocampus cause the decay of short-term fear memories in that brain region, without an overall memory loss. Read the rest of this entry »