Health & Wellness
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New connections begin to form between brain cells almost immediately as animals learn a new task, according to a new study.
New connections begin to form between brain cells almost immediately as animals learn a new task, according to a study published recently in
Nature. Led by researchers at the University of California, Santa Cruz, the study involved detailed observations of the rewiring processes that take place in the brain during motor learning.
The researchers studied mice as they were trained to reach through a slot to get a seed. They observed rapid growth of structures that form connections (called synapses) between nerve cells in the motor cortex, the brain layer that controls muscle movements.
"We found very quick and robust synapse formation almost immediately, within one hour of the start of training," said Yi Zuo, assistant professor of molecular, cell and developmental biology at UCSC.
Zuo's team observed the formation of structures called "dendritic spines" that grow on pyramidal neurons in the motor cortex. The dendritic spines form synapses with other nerve cells. At those synapses, the pyramidal neurons receive input from other brain regions involved in motor memories and muscle movements. The researchers found that growth of new dendritic spines was followed by selective elimination of pre-existing spines, so that the overall density of spines returned to the original level.
American doctors wrote more than 164 million prescriptions for antidepressants in 2008, making it the third-most-prescribed of any class of drugs. Now Bristol-Myers Squibb is tapping into that vast market with an aggressive advertising campaign for its blockbuster antipsychotic medication, Abilify.
Abilify was originally approved for treating schizophrenia and, soon after, bipolar disorder. But it hit the real jackpot in late 2007 when it won approval as an add-on treatment for people with major depression who haven't gotten adequate relief from taking an antidepressant alone. It's the first antipsychotic medicine approved by the Food and Drug Administration for that use.
Now the manufacturer of Abilify is advertising the drug's use in treating depression in print and on television, and it's working: U.S. sales of Abilify topped an incredible $2.37 billion last year, an increase of 33 percent from 2007, making it the 12th-highest earner among branded drugs.
While the ads may have worked to promote drug sales, the trouble is that anyone watching the TV ad would swear the drug is just another antidepressant. But Abilify isn't a common drug. It's a member of a class of drugs known as atypical (or "newer") antipsychotics. These medicines have different -- and, in some cases, considerably more serious -- side effects than the most common class of drugs used to treat depression, selective serotonin reuptake inhibitors, or SSRIs, which have plenty of safety concerns of their own.
Researchers using functional magnetic resonance imaging (fMRI) to study brain activation have found that men and women respond differently to positive and negative stimuli, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).
"Men may direct more attention to sensory aspects of emotional stimuli and tend to process them in terms of implications for required action, whereas women direct more attention to the feelings engendered by emotional stimuli," said Andrzej Urbanik, M.D., Ph.D., chair of Radiology at Jagiellonian University Hospital in Krakow, Poland.
For the study, Dr. Urbanik and colleagues recruited 40 right-handed volunteers, 21 men and 19 women, between the ages of 18 and 36. The volunteers underwent fMRI while viewing pictures from the International Affective Picture System (IAPS), a widely used, standardized testing system comprised of several thousand slides of various objects and images from ordinary life designed to evoke defined emotional states. The images were displayed in two runs. For the first run, only negative pictures were shown. For the second run, only positive pictures were shown.
Although recent advances have raised hopes that a protective vaccine can be developed, acquired immunodeficiency syndrome (AIDS) remains a major public health problem. Much has been learned about HIV-1, the virus that causes the disease. However, basic aspects of person-to-person transmission and of the progressive intercellular infection that depletes the immune system of its vital T cells remain imperfectly understood.
In a paper published November 6 in the online journal PloS Pathogens, Professor Don Lamb's group at the Ludwig-Maximilians-Universitaet (LMU) in Munichs's Department of Chemistry and Biochemistry, together with colleagues in Heidelberg, describe in detail how new virus particles assemble at the membrane of infected cells, and are released to attack healthy cells nearby. The new findings could help provide clues as how to interrupt the process of intercellular viral spread.
As many of us have learned from personal experience, computer viruses, which contain short pieces of malicious code and arrive in anonymous packages, can gum up data-processing routines. This definition also fits their biological counterparts, which generally comprise compact genomes packed in protein shells, and enter cells via specific portals. For example, the retrovirus HIV-1 has only nine genes in its RNA genome and infects cells by binding to specific receptors. Inside the cell, the genetic material is copied and 15 viral proteins are synthesized. They interact to pack the genomic RNA into new viral particles. These are then extruded from the cell, wrapped in an envelope of membrane bearing viral proteins that direct the parcel to the next susceptible cell.
How does our biological system know that it is supposed to operate on a 24-hour cycle? Scientists at the Hebrew University of Jerusalem have discovered that a tiny molecule holds the clue to the mystery.
Human as well as most living organisms on earth possess circadian a (24-hour) life rhythm. This rhythm is generated from an internal clock that is located in the brain and regulates many bodily functions, including the sleep-wake cycle and eating.
Although the evidence for their existence is obvious and they have been studied for more than 150 years, only recently the mechanisms that generate these rhythms have begun to be unraveled.
A researcher of the Alexander Silberman Institute of Life Sciences at the Hebrew University, Dr. Sebastian Kadener, and one of his students, Uri Weissbein, are among a collaborative group of researchers that have now found that tiny molecules known as miRNAs are central constituents of the circadian clock. Their discovery holds wide-ranging implications for future therapeutic treatment to deal with sleep deprivation and other common disorders connected with the daily life cycle.
Joene Hendry
ReutersSat, 28 Nov 2009 18:50 UTC
With the help of their doctors, women planning to become pregnant should take an inventory of the medications they take, researchers from Canada advise.
In a study, they found that many pregnant women still take medications long known to cause birth defects.
Some medications with known fetal risk, such as drugs that control epilepsy, are essential during pregnancy, Dr. Anick Berard, at the University of Montreal in Quebec, noted in an email correspondence to Reuters Health.
Other medications, such as those that treat severe acne, anxiety and psychiatric drugs, antibiotics, and many drugs prescribed for heart disease and medical conditions, "can and should be avoided," according to Berard.
The community-acquired strain of the deadly
Methicillin-resistant Staphylococcus aureus (MRSA) pathogen is presenting larger health issues than first believed, reports Science Daily. MRSA is a bacteria that can cause serious infection and is resistant to most antibiotics, noted Science Daily, citing a recent study in next month's issue of Emerging Infectious Diseases.
MRSA now has two main strains. The traditional, hospital-acquired MRSA (HA-MRSA), which, said
eFluxMedia in an earlier report, is more dangerous due to its overwhelming antibiotic resistance and community-acquired MRSA (CA-MRSA). CA-MRSA originates from strain ST8:USA300 and, while more potent, is a bit easier to treat, often not needing antibiotic therapy. Science Daily explained earlier, that MRSA are
Staphylococcus aureus bacteria that are resistant to the meticillin class of antibiotics.
The landscape of health has changed. No longer are our families guaranteed a healthy livelihood, not in the face of the current rates of cancer, diabetes, obesity, Alzheimer's and allergies. In the
words of Elizabeth Warren, Harvard University law professor who is head of the Congressional Oversight Panel, "We need a new model," and we need a new food system. It's our health on the line.
Paula Crossfield
Civil EatsSat, 28 Nov 2009 16:42 UTC
One thing we know for sure is that we just don't know enough about genetically modified organisms (GMOs) and biotechnology to know that in planting their seeds, we aren't affecting future generations' ability to feed themselves. For many people, the fact that they're corporately controlled and thus make for bad social policy, or that they genetically contaminate other species and as such increase claims against farmers, while undermining a farmer's ability to save seed and be self sufficient, are enough of an argument against their propagation. But in Claire Hope Cummings' excellent book,
Uncertain Peril: Genetic Engineering and the Future of Seeds, she weaves in the stories of the people and places behind a phenomenon that's gotten a few rich, while farmers struggle with shrinking margins.
Researchers from Newcastle University have scientifically
proven that
Hyptis crenata, also known as Brazilian mint, is a powerful pain reliever that works just as well as Indometacin, a synthetic drug similar to aspirin. A traditional remedy for treating the flu, stomach problems, high fevers, and headaches, Brazilian mint was found to be extremely powerful and safe.
The team, led by Graciela Rocha, set out to perform the study using the traditional preparation of the herb. Surveys were conducted in Brazil to figure out exactly how this was done and how much should be consumed in order to achieve beneficial results. The preparation the team ended up using consisted of the herb's dried leaves being steeped in boiling water for 30 minutes. Once cool, the tea was consumed in the same way as any other brewed tea would be. The results indicated efficacy in a wide range of ailments.
Graciela emphasized the fact that more than 50,000 plants worldwide are used for some type of medicinal purpose and that researchers should focus on identifying these types of plants and testing their efficacy. Since more than half of all prescription drugs are derived from plant compounds, it is a worthy effort to study plant medicines in their natural, safe forms.
