Researchers watch brain in action

For the first time, scientists have been able to watch neurons within the brain of a living animal change in response to experience.

Thanks to a new imaging system, researchers at MIT’s Picower Institute for Learning and Memory have gotten an unprecedented look into how genes shape the brain in response to the environment. Their work is reported in the July 28 issue of Cell.

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Researchers calculate human eye transmits information to the brain at the rate of an ethernet

Researchers at the University of Pennsylvania School of Medicine estimate that the human retina can transmit visual input at about the same rate as an Ethernet connection, one of the most common local area network systems used today. They present their findings in the July issue of Current Biology. This line of scientific questioning points to ways in which neural systems compare to artificial ones, and can ultimately inform the design of artificial visual systems.

Two broad classes of ganglion cell types in the guinea pig retina: brisk cells, which are larger and transmit electrical impulses faster, and sluggish, which are smaller and slower

Nano Probe May Open New Window Into Cell Behavior

Georgia Tech researchers have created a nanoscale probe, the Scanning Mass Spectrometry (SMS) probe, that can capture both the biochemical makeup and topography of complex biological objects in their normal environment — opening the door for discovery of new biomarkers and improved gene studies, leading to better disease diagnosis and drug design on the cellular level. The research was presented in the July issue of IEE Electronics Letters.

Georgia Tech’s SMS Probe gently pulls biomolecules precisely at a specific point on the cell/tissue surface, ionizes these biomolecules and produces “dry” ions suitable for analysis and then transports those ions to the mass spectrometer.

DNA damage study probes inflammation, disease link

New research at MIT may help scientists better understand the chemical associations between chronic inflammation and diseases such as cancer and atherosclerosis. The work could lead to drugs that break the link between the two.

Researchers transform stem cells found in human fat into smooth muscle cells

Researchers at UCLA today announced they have transformed adult stem cells taken from human adipose – or fat tissue – into smooth muscle cells, which help the normal function of a multitude of organs like the intestine, bladder and arteries. The study may help lead to the use of fat stem cells for smooth muscle tissue engineering and repair.
Reported in the July 24 online edition of the Proceedings of the National Academy of Sciences, the study is one of the first to show that stem cells derived from adipose tissue can be changed to acquire the physical and biochemical characteristics as well as the functionality of smooth muscle cells.

Scientists Discover Key to Growing New Stem Cells

Scientists at Duke University Medical Center have demonstrated they can grow human stem cells in the laboratory by blocking an enzyme that naturally triggers stem cells to mature and differentiate into specialized cells.
The discovery may enable scientists to rapidly grow stem cells and transplant them into patients with blood disorders, immune defects and select genetic diseases, said the Duke researchers.

Researchers Show How Brain Decodes Complex Smells

Duke University Medical Center researchers have discovered how the brain creates a scent symphony from signals sent by the nose.

In studies in mice, the researchers found that nerve cells in the brain’s olfactory bulb — the first stop for information from the nose — do not perceive complex scent mixtures as single objects, such as the fragrance of a blooming rose. Instead, these nerve cells, or neurons, detect the host of chemical compounds that comprise a rose’s perfume. Smarter sections of the brain’s olfactory system then categorize and combine these compounds into a recognizable scent. According to the researchers, it’s as if the brain has to listen to each musician’s melody to hear a symphony.

Humans may rely on the same smell decoding system, because mice and men have similar brain structures for scent, including an olfactory bulb, the researchers said.

Researchers Find New Clues To Biochemistry Of ‘Anti-Aging

University of Wisconsin-Madison researchers have found that sirtuins, a family of enzymes linked to a longer life span and healthier aging in humans, may orchestrate the activity of other enzymes involved in metabolic processes in the body.
Published in the Proceedings of the National Academy of Sciences, the study is the first to show that sirtuins directly control specific metabolic enzymes – called AceCSs – in mammalian cells.

The finding, which shines a spotlight on enzymes only recently thought to play a role in the biochemistry of “anti-aging,” has attracted the interest of biotechnology companies seeking to make drugs that delay the aging process and age-related diseases. The drugs could target the metabolic enzymes to produce health benefits.

Study finds potential ovarian cancer stem cells

Massachusetts General Hospital (MGH) researchers have identified potential ovarian cancer stem cells, which may be behind the difficulty of treating these tumors with standard chemotherapy. Understanding more about the stem-like characteristics of these cells could lead to new approaches to treating ovarian cancer, which kills more than 16,000 U.S. women annually and is their fifth most common cause of cancer death. The report will appear in the July 25 Proceeding of the National Academy of Sciences (PNAS) and has received early online release.

Scientists find rate of aging is at least in part genetically determined

We can dye gray hair, lift sagging skin or boost lost hearing, but no visit to the day spa would be able to hide a newly discovered genetic marker for the toll that time takes on our cells. “We’ve found something that is at the core of aging,” said Stuart Kim, PhD, professor of developmental biology and of genetics at the Stanford University School of Medicine.

In a study to be published in the July 21 issue of Public Library of Science-Genetics, Kim and colleagues report finding a group of genes that are consistently less active in older animals across a variety of species. The activity of these genes proved to be a consistent indicator of how far a cell had progressed toward its eventual demise.

Researchers develop T-cells from human embryonic stem cells

Researchers from the UCLA AIDS Institute and the Institute for Stem Cell Biology and Medicine have demonstrated for the first time that human embryonic stem cells can be genetically manipulated and coaxed to develop into mature T-cells, raising hopes for a gene therapy to combat AIDS.

The study, to be published the week of July 3 in the online edition of the Proceedings of the National Academy of Sciences, found that it is possible to convert human embryonic stem cells into blood-forming stem cells that in turn can differentiate into the helper T-cells that HIV specifically targets. T-cells are one of the body’s main defenses against disease.

Researchers find new way to open ion channels in cell membranes

Using an enzyme found in the venom of the brown recluse spider, researchers at the University of Pennsylvania School of Medicine have discovered a new way to open molecular pores, called ion channels, in the membrane of cells. The research team screened venoms from over 100 poisonous invertebrate species to make this discovery.

The enzyme, sphingomyelinase D (SMase D), splits a lipid called sphingomyelin that surrounds the channel embedded in the cell membrane. As a result, the channel opens to allow the passage of small ions into and out of the cell, thereby generating electrical currents.

Scientists Discover a Genetic Code for Organizing DNA

DNA – the long, thin molecule that carries our hereditary material – is compressed around protein scaffolding in the cell nucleus into tiny spheres called nucleosomes. The bead-like nucleosomes are strung along the entire chromosome, which is itself folded and packaged to fit into the nucleus. What determines how, when and where a nucleosome will be positioned along the DNA sequence?

Dr. Eran Segal and research student Yair Field of the Computer Science and Applied Mathematics Department at the Weizmann Institute of Science have succeeded, together with colleagues from Northwestern University in Chicago, in cracking the genetic code that sets the rules for where on the DNA strand the nucleosomes will be situated. Their findings appeared today in Nature.

Sperm created in the laboratory from embryonic stem cells produce viable progeny

Scientists have demonstrated for the first time that embryonic stem (ES) cells cultured in the laboratory can produce sperm with the capacity to produce viable offspring. The research, published in the July issue of Developmental Cell, opens many exciting avenues for future studies, including investigation of mechanisms involved in sperm production and development of new treatment strategies for infertility.

Engineers Use DNA to Direct Nanowire Assembly and Growth

A growing number of engineers are using nature’s engineer – DNA – to create nanomaterials that can be used in everything from medical devices to computer circuits. A team from Brown University and Boston College is the first to use DNA to direct construction and growth of complex nanowires. Their work appears in Nanotechnology.

Controlling movement through thought alone

A man with paralysis of all four limbs could directly control objects around him – open simulated email, play a game of Pong, adjust the volume on the television set – using only his thoughts. These pilot clinical trial findings, featured on the cover of Nature, mark a major advance in neuroscience, one that offers hope to people with severe motor impairments.

Natural vitamin E tocotrienol reaches blood at protective levels

Two recent studies offer new evidence suggesting an alternative form of natural vitamin E can be taken by mouth and will reach the blood in humans at levels determined to protect against stroke and other diseases.
Vitamin E occurs naturally in eight different forms. The primary vitamin E on drugstore shelves is called tocopherol, or TCP. But another natural form of vitamin E surfacing as a potent neuroprotective agent in repeated Ohio State University Medical Center studies is tocotrienol, or TCT.

The aging-clock connection

In the July 15th issue of G&D, Dr. Marina Antoch and colleagues (The Lerner Research Institute) establish a link between the innate biological clock – known as the circadian clock – and aging.

Fat-generated hormone drives energetic capacity of muscle

The fat-generated hormone adiponectin plays an important role in the energetic capacity of skeletal muscle, according to a new study in the July, 2006, Cell Metabolism, published by Cell Press. Adiponectin is unusual among fat hormones in that its levels generally decline in those who are obese.

The researchers report evidence in people and mice, linking low adiponectin levels to insulin resistance and reductions in the number of “cellular power plants” called mitochondria in skeletal muscle. The findings suggest that therapies designed to boost the adiponectin signal might prove beneficial for the treatment of insulin resistance and diabetes, they said.

Scientists reveal possible strategy against obesity, diabetes and infertility

Twelve years ago, scientists discovered leptin–the now-famous hormone that controls appetite, burns calories and performs other crucial physiological activities as well. But the precise mechanism(s) by which leptin carries out these metabolic tasks is still controversial. Now, researchers at the Albert Einstein College of Medicine of Yeshiva University have shown how leptin exerts some of its most important effects.

Their findings, reported in the July 5 issue of Cell Metabolism, suggest a novel approach for duplicating leptin’s actions when the body no longer responds to the hormone.

Medium is the message for stem cells in search of identities

Embryonic stem cells, prized for their astonishing ability to apparently transform into any kind of cell in the body, acquire their identities in part by interacting with their surroundings – even when they are outside of the body in a laboratory dish, University of Florida scientists report.

Using an animal model of embryonic stem cell development, researchers with UF’s McKnight Brain Institute have begun to answer one of the most fundamental questions in science – how does a batch of immature cells give rise to an organ as extraordinarily complex as the human brain?

The findings, to be published this week in the Proceedings of the National Academy of Sciences, may one day help scientists create laboratory environments to grow specialized cells that can be transplanted into patients to treat epilepsy, Parkinson’s, Huntington’s and Alzheimer’s diseases or other brain disorders.