neuroscience
edyong | September 3, 2009As sufferers of post-traumatic stress syndrome know all too well, frightening experiences can be strong, long-lasting and notoriously difficult to erase. Now, we're starting to understand why. Far from trying to purge these memories, the brain actively protects them by hiring a group of molecular bodyguards called CSPGs (or chondroitin sulphate proteoglycans in full).
By studying the brains of rats, Nadine Gogolla from Harvard University found that CSPGs - large chains of sugars and proteins - accumulate in the space around nerve cells and form defensive nets around a select few. Dissolve…
terrasig | August 31, 2009
The Boulder County coroner announced today that the July death of a Boulder teen was indeed due to opioid intoxication from preparation of a poppy pod tea.
Jeffrey Joseph Bohan, 19, of Boulder, was found dead in his friend's Boulder home about 6 p.m. July 21 after drinking poppy-pod tea the night before with his brother, according to Boulder police.
Investigators suspected the Fairview High graduate, who was going to Colorado State University, died from the psychoactive tea, which is brewed from the plant that produces opium. But they couldn't be sure until the Coroner's Office confirmed…
edyong | August 30, 2009We all have a personal bubble, an invisible zone of privacy around our bodies. When strangers cross this boundary, it makes us feel uncomfortable. But not all of us - Daniel Kennedy from the California Institute of Technology has been studying a woman known only as SM, who lacks any sense of personal space.
SM suffers from a rare genetic disorder called Urbach-Wiethe disease, that causes parts of the brain's temporal lobes to harden and waste away. This brain damage has completely destroyed SM's amygdalae, a pair of small, almond-shaped structures that help us to process emotions.
Kennedy…
neurophilosophy | August 27, 2009THE retina has an inverted structure which seems ill-suited to its function: the rod and cone cells, which are sensitive to light, and which convert light energy into electrical impulses, point backwards and are located at the back of the retina, so that light entering the eye has to pass through several layers of irregularly organized cells before it reaches them. The retina also contains nerve fibres which are positioned perpendicular to the path of light entering the eye, and many of the structures in the upper cell layers have a diameter similar to that of the wavelength of visible light…
neurophilosophy | August 26, 2009
THIS weird and wonderful creature is the star-nosed mole (Condylura cristata), a small, semi-aquatic mammal which inhabits the low wetlands of eastern North America. Like other moles, it ekes out an existence in a network of narrow underground tunnels, and digs shallow surface tunnels where it forages for insects, worms and molluscs. Living as it does in almost complete darkness, the star-nosed mole has poorly developed eyes, and is virtually blind. Instead, it relies heavily on its remarkable star-shaped nose. This organ enables the star-nosed mole to decide whether something is edible with…
edyong | August 24, 2009Our minds are battlegrounds where different media fight for attention. Through the Internet, desktops, mobile screens, TVs and more, we are constantly awash with headlines, links, images, icons, videos, animations and sound. This is the way of the 21st century - a saturated sensory environment where multi-tasking is the name of the game. Even as I type these words, my 24-inch monitor displays a Word document and a PDF side-by-side, while my headphones pump Lux Aeterna into my head (see image below).
You might think that this influx of media would make the heaviest of users better at…
edyong | August 19, 2009Whether it's a goalkeeper who needs to decide which way to dive, or a motorist who needs to swerve to avoid a pedestrian, people often have to make decisions in a small amount of time, based on a complex onrush of information. But even as their muscles launch them towards one particular fate, there is still room for indecisiveness. Arbora Resulaj from the University of Cambridge has found that people often change their decisions in the split-seconds after making them because of late-arriving information.
Neuroscientists have come up with several possible explanations for what happens in…
j7uy5 | August 19, 2009It is refreshing to see something like this. Both drugs are
available as generics, so the financial motivation for a study like
this is not great. But the clinical benefit could e substantial,
albeit for a small subset of patients.
Clozapine is considered to be the most efficacious antipsychotic
medication, in that it is the drug to which the highest percentage of
persons with psychosis have a positive response. It is, however,
considered a third-line drug. The reason is that about 1% of
patients will develop severe granulocytopenia. So, in general, a
patient will be tried on at least…
bioephemera | August 16, 2009I read Scibling Jonah Lehrer's How We Decide some time ago, but Moveable Type ate my half-finished review, and it's taken me until now to get back to it. You may have seen quite a few reviews elsewhere by now - Adam Kepecs reviewed it for Nature back in April, and to make a long story short, I largely agree with him: Lehrer is a very good writer, but this is not a great book.
Lehrer starts his book with an airplane anecdote, so I'll do the same - although his opening anecdote is about crashing a plane (albeit a simulated plane), so I'm not sure I'd recommend the book for nervous flyers.…
bioephemera | August 15, 2009
Photographer: Rudy Huhold
Agency: Artplan
Apparently package delivery service Sedex Express is quite similar to. . . your brain on drugs. Hmmmm.
Via fubiz
neurophilosophy | August 11, 2009AS Seed's Featured Blogger of the week, I have written a short article about the Human Connectome Project, in response to a news story on the magazine's website, called Mapping the brain's highways, by Azeen Ghorayshi.
Several weeks ago, the National Institutes of Health announced the Human Connectome Project, an ambitious $30 million five-year initiative, which aims to map the connectivity of the human brain.
Is this feasible? In short, the answer is no. The idea that a complete connectivity map of the whole brain can be achieved within five years is unrealistic, and producing a…
edyong | August 10, 2009People infected with the bird flu virus - influenza A subtype H5N1 - go through the usual symptoms of fever, aching muscles and cough. The virus is so virulent that 60% of infected humans have died. But according to a study in mice, the infection could also take a more inconspicuous toll on the brain, causing the sorts of damage that could increase the risk of diseases like Parkinson's and Alzheimer's many years after the virus has been cleared.
The link between influenza and Parkinson's disease is hardly old but certainly controversial. Previous studies have found no traces of flu genetic…
edyong | August 7, 2009Itching is an unpleasant sensation that drives us to scratch reflexively in an effort to remove harmful substances from our body. It's also how I get most of my physical activity for the day. Not being able to scratch an itch is intensely frustrating and many scientists have long described itch as the milder cousin of pain.
But a team of scientists from Washington University's Pain Center (I wonder if they have problems with recruitment) have discovered a group of neurons in the spines of mice that are specific to itch but not to pain. Remove them, and mice hardly ever scratch when they're…
bioephemera | August 5, 2009So on my return to regular Scienceblogging, I see that Mike the Mad Biologist and Razib are taking exception to a point made by Megan McArdle in the Atlantic. McArdle observes that the heritability of weight is quite high - almost as high as the heritability of height:
Twin studies and adoptive studies show that the overwhelming determinant of your weight is not your willpower; it's your genes. The heritability of weight is between .75 and .85. The heritability of height is between .9 and .95. And the older you are, the more heritable weight is.
Okay: how you take that statement depends…
j7uy5 | August 3, 2009There is a short
open-access article about whole-body neuronal MRI, in the most recent
NEJM. The authors describe a technique of visualizing peripheral
nerves. Normally, these are not seen very well on MRI. This
limits the usefulness of MR imaging for nerves outside of the central
nervous system.
The two images on the left are from a person with no neurological
disease. The two on the right show a person with
href="http://scienceblogs.com/effectmeasure/2008/04/disease_at_the_head_table_seco.php">chronic
inflammatory demyelinating polyneuropathy (CIDP). You can see
a bigger version…
ejohnson | July 28, 2009Dope A. Mean and the Glut-Tang Clan may not be a household name yet, but if the debut video of their smash hit Synaptic Cleft is any indication, they're poised to be the breakout group of the summer.
S to the YNAPSE!
edyong | July 28, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science.
The idea of an out-of-body experiences seems strange and hokey - certainly not one that would grace one of the world's top scientific journals. So it may seem surprising that two years ago, Science published not one, but two papers that considered the subject through the lens of scientific scrutiny.
Out-of-body experiences are rare and can be caused by epileptic fits, neurological conditions such as strokes and heavy drug abuse. Clearly, they are triggered when something goes wrong in our brains.…
j7uy5 | July 27, 2009Natalie Angier has another
href="http://www.nytimes.com/2009/07/21/science/21angier.html?sq=behavior%20what%20animals%20do&st=cse&scp=1&pagewanted=print">interesting
article in the NYT. In the article, she discusses the meaning
of the word behavior. Apparently, this all came from the
realization that even standard works on the subject did not contain a
"point-by-point definition."
The realization came to
href="http://dlevitis.org/dlevitis/Research.html">Dan Levitis, a
grad student in zoology at Berkeley. Levitis happens to have a
Blogspot blog: Blog of
Science; he's…
edyong | July 23, 2009From the scientists who brought you the infamous 'Halle Berry neuron' and the 'Jennifer Aniston neuron' come the 'Oprah Winfrey neuron' and the 'Saddam Hussein neuron'.
Four years ago, Rodrigo Quian Quiroga from Leicester University showed that single neurons in the brain react selectively to the faces of specific people, including celebrities like Halle Berry, Jennifer Aniston and Bill Clinton. Now, he's back, describing single neurons that respond selectively to the concept of Saddam Hussein or Oprah Winfrey. This time, Quiroga has found that these neurons work across different senses,…
edyong | July 22, 2009
This is a repost from the old Wordpress incarnation of Not Exactly Rocket Science
You are being hunted, chased through a labyrinth by a relentless predator. Do you consider your options and plan the best possible escape, or do you switch off and rely solely on instinct? A new study provides the answer - you do both, flicking from one to the other depending on how far away the threat is.
Earlier studies have found that different parts of a rodent's brain are activated in the face of danger, depending on how imminent that danger is. Now, scientists at University College London has found the…