Pavlov’s Neurons: Brain Cells That Are A Key To Learning Discovered

More than a century after Ivan Pavlov’s dog was conditioned to salivate when it heard the sound of a tone prior to receiving food, scientists have found neurons that are critical to how people and animals learn from experience.

Using a new imaging technique called Arc catFISH, researchers from the University of Washington have visualized individual neurons in the amygdalas of rat brains that are activated when the animals are given an associative learning task.

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Scientists find potential strategy to eliminate poisonous protein from Alzheimer brains

Scientists at the Gladstone Institute of Neurological Disease (GIND) have identified a new strategy to destroy amyloid-beta (AB) proteins, which are widely believed to cause Alzheimer’s disease (AD). Li Gan, PhD, and her coworkers discovered that the activity of a potent AB-degrading enzyme can be unleashed in mouse models of the disease by reducing its natural inhibitor cystatin C (CysC).

Researchers identify Achilles heel of common childhood tumor

Researchers have discovered a mechanism for the rapid growth seen in infantile hemangioma, the most common childhood tumor.

The tumors, which are made up of proliferating blood vessels, affect up to 10 percent of children of European descent, with girls more frequently afflicted than boys. The growths appear within days of birth—most often as a single, blood-red lump on the head or face—then grow rapidly in the ensuing months. The development of infantile hemangioma slows later in childhood, and most tumors disappear entirely by the end of puberty. However, while the tumors are benign, they can cause disfigurement or clinical complications. This new research offers hope for the most severe of these cases, pointing at a potential, non-invasive treatment for the condition.

Emotion and scent create lasting memories – even in a sleeping brain

When French memoirist Marcel Proust dipped a pastry into his tea, the distinctive scent it produced suddenly opened the flood gates of his memory.

In a series of experiments with sleeping mice, researchers at the Duke University Medical Center have shown that the part of the brain that processes scents is indeed a key part of forming long-term memories, especially involving other individuals.

Can genetic information be controlled by light?

DNA, the molecule that acts as the carrier of genetic information in all forms of life, is highly resistant against alteration by ultraviolet light, but understanding the mechanism for its photostability presents some puzzling problems. A key aspect is the interaction between the four chemical bases that make up the DNA molecule. Researchers at Kiel University have succeeded in showing that DNA strands differ in their light sensitivity depending on their base sequences. Their results are reported by Nina Schwalb and colleagues in the current issue of the journal Science appearing on October 10, 2008.

Study unlocks stem cell DNA secrets

In a groundbreaking study led by an eminent molecular biologist at Florida State University, researchers have discovered that as embryonic stem cells turn into different cell types, there are dramatic corresponding changes to the order in which DNA is replicated and reorganized.

The findings bridge a critical knowledge gap for stem cell biologists, enabling them to better understand the enormously complex process by which DNA is repackaged during differentiation — when embryonic stem cells, jacks of all cellular trades, lose their anything-goes attitude and become masters of specialized functions.

Searching For HIV’s Achilles Heel

Why is it so hard to make an HIV vaccine? Dr. John Coffin, who is one of the fathers of modern retrovirology,  Professor of Molecular Biology and Microbiology at Tufts University asks in his insightful blog article, full of humor and historical metaphors. Dr. Coffin proposes that the answer to this question, which has eluded us for the last 25 years, lies in the unusual relationship of this particular virus with its host. He explains variety of ingenious ways HIV is able to evade the immune system and how it has evolved to exploit it for its own benefit.

Despite incredible challenges remaining to find this HIV’s Achilles, Dr. Coffin maintains his optimism for overcoming these: ” Given the obvious need for effective prevention to stem the AIDS pandemic, we must keep trying. Unfortunately, HIV has evolved into a niche whose very properties seem designed to thwart our attempts to turn the immune system against it. As an article of faith, we must believe that there is an Achilles’ heel in the virus’s sugary armor that we can exploit, but we haven’t found it yet.”

Read this excellent article at Small Things considered: the microbe blog.

When a light goes on during thought processes

Thought processes made visible: An international team of scientists headed by Mazahir Hasan of the Max Planck Institute for Medical Research in Heidelberg has succeeded in optically detecting individual action potentials in the brains of living animals.

The scientists introduced fluorescent indicator proteins into the brain cells of mice via viral gene vectors: the illumination of the fluorescent proteins indicates both when and which neurons are communicating with each other. This new method enables the observation of brain activity over a period of many months and provides new ways of identifying, for example, the early onset of dysfunction in neurological disorders such as Alzheimer’s and Parkinson’s. The fluorescent proteins could also provide scientists with information about the ways in which normal aging processes affect nerve cell communication (Nature Methods, September 2008).

Scientists identify a molecule that coordinates the movement of cells

Even cells commute. To get from their birthplace to their work site, they sequentially attach to and detach from an elaborate track of exceptionally strong proteins known as the extracellular matrix. Now, in research to appear in the October 3 issue of Cell, scientists at the Howard Hughes Medical Institute and Rockefeller University show that a molecule, called ACF7, helps regulate and power this movement from the inside – findings that could have implications for understanding how cancer cells metastasize.

The ‘satellite navigation’ in our brains

Our brains contain their own navigation system much like satellite navigation (“sat-nav”), with in-built maps, grids and compasses, neuroscientist Dr Hugo Spiers told the BA Festival of Science at the University of Liverpool today.

The brain’s navigation mechanism resides in an area know as the hippocampus, which is responsible for learning and memory and famously shown to be different in London taxi drivers in a Wellcome Trust-funded study carried out by Professor Eleanor Maguire at UCL (University College London).

Tuberculosis drug shows promise against latent bacteria

A new study has shown that an investigational drug (R207910, currently in clinical trials against multi-drug resistant tuberculosis strains) is quite effective at killing latent bacteria. This revelation suggests that R207910 may lead to improved and shortened treatments for this globally prevalent disease.

Researchers find memory capacity much bigger than previously thought

Subjects in memory tests given at MIT’s Computational Vision Cognition Laboratory were asked to recall which of a pair of objects they had seen earlier that day. Subjects were shown 3,000 images, one at a time, over a five-hour period.

Image courtesy / Computational Vision Cognition Laboratory, MIT

How memories are made, and recalled

What makes a memory? Single cells in the brain, for one thing. For the first time, scientists at UCLA and the Weizmann Institute of Science in Israel have recorded individual brain cells in the act of calling up a memory, thus revealing where in the brain a specific memory is stored, and how it is able to recreate it.

Reporting in the current edition of the journal Science, Dr. Itzhak Fried, senior author and a UCLA professor of neurosurgery, and colleagues, recorded the activity of hundreds of individual neurons making memories from the brains of 13 epilepsy patients being treated at the UCLA Medical Center. The patients’ surgeons had placed electrodes into their brains to locate the origin of their seizures before surgical treatment (standard procedure in such cases).

Learning Suffers If Brain Transcript Isn’t Transported Far Out To End Of Neurons

Neuroscientists at Georgetown University Medical Center have solved a mystery that lies at the heart of human learning, and they say the solution may help explain some forms of mental retardation as well as provide clues to overall brain functioning.

Trigger For Brain Plasticity Identified

Researchers have long sought a factor that can trigger the brain’s ability to learn – and perhaps recapture the “sponge-like” quality of childhood. In the August 8 issue of the journal Cell, neuroscientists at Children’s Hospital Boston report that they’ve identified such a factor, a protein called Otx 2.

Otx2 helps a key type of cell in the cortex to mature, initiating a critical period — a window of heightened brain plasticity, when the brain can readily make new connections.

3D Animation explaining basics of the human genome

A dynamic 3D computer animated video takes you “inside” for a close-up look at how we’re made.  3D modeling and animation created by Bill Baker, Bakedmedia, Inc. and Mike Fisher for the National Human Genome Research Institute.

Prevailing theory of aging challenged in worm study

Age may not be rust after all. Specific genetic instructions drive aging in worms, report researchers at the Stanford University School of Medicine. Their discovery contradicts the prevailing theory that aging is a buildup of tissue damage akin to rust, and implies science might eventually halt or even reverse the ravages of age.

A new cellular pathway linked to cancer

In the life of a cell, the response to DNA damage determines whether the cell is fated to pause and repair itself, commit suicide, or grow uncontrollably, a route leading to cancer. In a new study, published in the July 25th issue of Cell, scientists at NYU Langone Medical Center have identified a way that cells respond to DNA damage through a process that targets proteins for disposal. The finding points to a new pathway for the development of cancer and suggests a new way of sensitizing cancer cells to treatment.

Genes That Control Embryonic Stem Cell Fate Identified

Scientists have identified about two dozen genes that control embryonic stem cell fate. The genes may either prod or restrain stem cells from drifting into a kind of limbo, they suspect. The limbo lies between the embryonic stage and fully differentiated, or specialized, cells, such as bone, muscle or fat.

By knowing the genes and proteins that control a cell’s progress toward the differentiated form, researchers may be able to accelerate the process — a potential boon for the use of stem cells in therapy or the study of some degenerative diseases, the scientists say.

JoVE, the video-publication for biological research, is now listed on PubMed

I had posted on this really cool online video journal called Jove which is sort of like Youtube for scientists. The scientific videos are peer reviewed and is now also accepted for indexing in PubMed and MEDLINE. Great idea and implementation.

Biology enters ‘The Matrix’ through new computer language

Ever since the human genome was sequenced less than 10 years ago, researchers have been able to access a dizzying plethora of genomic information with a simple click of a mouse. This digitizing of genomic data—and its public access—is something that would have been unthinkable a generation earlier.

Major Step Forward In Understanding How Memory Works

Our ability to remember the objects, places and people within our environment is essential for everyday life, although the importance of this is only fully appreciated when recognition memory beings to fail, as in Alzheimer’s disease.

By blocking certain mechanisms that control the way that nerve cells in the brain communicate, scientists from the University of Bristol have been able to prevent visual recognition memory in rats.

A single neuron (centre) in the perirhinal cortex which is involved in memory processes. (Credit: Photo by Andy Doherty)