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Scientists Take Step Toward Mapping How the Brain Stores Memories

A new study led by scientists at The Scripps Research Institute (TSRI) sheds light on how the brain stores memories. The research, published recently in the journal eLife, is the first to demonstrate that the same brain region can both motivate a learned behavior and suppress that same behavior.

“We behave the way we do in a specific situation because we have learned an association—a memory—tying an environmental cue to a behavior,” said Nobuyoshi Suto, TSRI Assistant Professor of Molecular and Cellular Neuroscience, who co-led the study with TSRI Professor Friedbert Weiss and Bruce Hope, a principal investigator at the National Institutes of Health’s National Institute on Drug Abuse. “This study provides causal evidence that one brain region can store different memories.”

Scientists know that our memories are stored in specific areas of the brain, but there has been some debate over whether a single brain region can store different memories that control opposing behavior. For example, can the same region store the meanings of red and green traffic lights—the memories that make a driver stop a car at a red light, then hit the gas pedal at a green light?

Suto’s research focuses specifically on the brain circuits that control motivation. In the new study, he and his colleagues set out to examine how rats learn to press levers to get sugar water—and where they store those motivational memories.

The researchers first trained the rats to press a lever to get sugar water. The researchers then trained the rats to recognize two colored lights: one signaling the availability of sugar reward, and the other signaling the omission of this reward. As a consequence, the animals learned to change their behavior in response to these cues: the cue signaling availability promoted the lever-pressing, while the cues signaling omission suppressed this reward-seeking behavior.

Based on previous electrophysiology studies, Suto and his colleagues speculated that memories associated with these two lessons were both stored in a region of the brain called the infralimbic cortex.

“We’ve seen correlational evidence, where we see brain activity together with a behavior, and we connect the dots to say it must be this brain activity causing this behavior,” said Suto. “But such correlational evidence alone cannot establish the causality—proof that the specific brain activity is directly controlling the specific behavior.”

So scientists took their experiment a step further. Using a pharmacogenetics approach, the researchers selectively switched off specific groups of brain cells—called neural ensembles—that react to select cues signaling either reward availability or reward omission.

The experiments demonstrated that distinct neural ensembles in the same region directly controlled the promotion of reward-seeking or the suppression of that behavior. Without those neurons firing, the rats no longer performed the behavior motivated by the memories in those ensembles. At last, the scientists appeared to prove the causality.

Suto called the findings a step towards understanding how different memories are stored in the brain. He said the research could also be relevant for studying which neurons are activated to motivate—and prevent—drug relapse. He said he’d next like to look at what other regions in the brain these infralimbic cortex neurons may be communicating with. “Brain regions don’t exist in a vacuum,” he said. In addition, he also would like to determine the brain chemicals mediating the promotion or suppression of reward seeking.

Solar System: 5 Things To Know This Week

Our solar system is huge, so let us break it down for you. Here are 5 things to know this week: 

1. Make a Wish

The annual Leonids meteor shower is not known for a high number of “shooting stars” (expect as many as 15 an hour), but they’re usually bright and colorful. They’re fast, too: Leonids travel at speeds of 71 km (44 miles) per second, which makes them some of the fastest. This year the Leonids shower will peak around midnight on Nov. 17-18. The crescent moon will set before midnight, leaving dark skies for watching. Get more viewing tips HERE.

2. Back to the Beginning

Our Dawn mission to the dwarf planet Ceres is really a journey to the beginning of the solar system, since Ceres acts as a kind of time capsule from the formation of the asteroid belt. If you’ll be in the Washington DC area on Nov. 19, you can catch a presentation by Lucy McFadden, a co-investigator on the Dawn mission, who will discuss what we’ve discovered so far at this tiny but captivating world. Find out how to attend HERE. 

3. Keep Your Eye on This Spot

The Juno spacecraft is on target for a July 2016 arrival at the giant planet Jupiter. But right now, your help is needed. Members of the Juno team are calling all amateur astronomers to upload their telescopic images and data of Jupiter. This will help the team plan their observations. Join in HERE.

4. The Ice Volcanoes of Pluto

The more data from July’s Pluto flyby that comes down from the New Horizons spacecraft, the more interesting Pluto becomes. The latest finding? Possible ice volcanoes. Using images of Pluto’s surface to make 3-D topographic maps, scientists discovered that some mountains on Pluto, such as the informally named Piccard Mons and Wright Mons, had structures that suggested they could be cryovolcanoes that may have been active in the recent geological past.

5. Hidden Storm

Cameras aboard the Cassini spacecraft have been tracking an impressive cloud hovering over the south pole of Saturn’s moon Titan. But that cloud has turned out to be just the tip of the iceberg. A much more massive ice cloud system has been found lower in the stratosphere, peaking at an altitude of about 124 miles (200 kilometers).

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

DIY USB Smartcard Lock (keyboard/mouse lock) controlled by phone-cards (by pcbheaven)

Project Site: Here

# ‘tis but a scratch | Python

// let it go | Swift

Helping Hand

Robots, video games, and a radical new approach to treating stroke patients.

BY KAREN RUSSELL

In late October, when the Apple TV was relaunched, Bandit’s Shark Showdown was among the first apps designed for the platform. The game stars a young dolphin with anime-huge eyes, who battles hammerhead sharks with bolts of ruby light. There is a thrilling realism to the undulance of the sea: each movement a player makes in its midnight-blue canyons unleashes a web of fluming consequences. Bandit’s tail is whiplash-fast, and the sharks’ shadows glide smoothly over rocks. Every shark, fish, and dolphin is rigged with an invisible skeleton, their cartoonish looks belied by the programming that drives them—coding deeply informed by the neurobiology of action. The game’s design seems suspiciously sophisticated when compared with that of apps like Candy Crush Soda Saga and Dude Perfect 2.

Bandit’s Shark Showdown’s creators, Omar Ahmad, Kat McNally, and Promit Roy, work for the Johns Hopkins School of Medicine, and made the game in conjunction with a neuroscientist and neurologist, John Krakauer, who is trying to radically change the way we approach stroke rehabilitation. Ahmad told me that their group has two ambitions: to create a successful commercial game and to build “artistic technologies to help heal John’s patients.” A sister version of the game is currently being played by stroke patients with impaired arms. Using a robotic sling, patients learn to sync the movements of their arms to the leaping, diving dolphin; that motoric empathy, Krakauer hopes, will keep patients engaged in the immersive world of the game for hours, contracting their real muscles to move the virtual dolphin.

Many scientists co-opt existing technologies, like the Nintendo Wii or the Microsoft Kinect, for research purposes. But the dolphin simulation was built in-house at Johns Hopkins, and has lived simultaneously in the commercial and the medical worlds since its inception. “We depend on user feedback to improve the game for John’s stroke patients,” Ahmad said. “This can’t work without an iterative loop between the market and the hospital.”

In December, 2010, Krakauer arrived at Johns Hopkins. His space, a few doors from the Moore Clinic, an early leader in the treatment of AIDS, had been set up in the traditional way—a wet lab, with sinks and ventilation hoods. The research done in neurology departments is, typically, benchwork: “test tubes, cells, and mice,” as one scientist described it. But Krakauer, who studies the brain mechanisms that control our arm movements, uses human subjects. “You can learn a lot about the brain without imaging it, lesioning it, or recording it,” Krakauer told me. His simple, non-invasive experiments are designed to produce new insights into how the brain learns to control the body. “We think of behavior as being the fundamental unit of study, not the brain’s circuitry. You need to study the former very carefully so that you can even begin to interpret the latter.”

Krakauer wanted to expand the scope of the lab, arguing that the study of the brain should be done in collaboration with people rarely found on a medical campus: “Pixar-grade” designers, engineers, computer programmers, and artists. Shortly after Krakauer arrived, he founded the Brain, Learning, Animation, Movement lab, or BLAM! That provocative acronym is true to the spirit of the lab, whose goal is to break down boundaries between the “ordinarily siloed worlds of art, science, and industry,” Krakauer told me. He believes in “propinquity,” the ricochet of bright minds in a constrained space. He wanted to create a kind of “neuro Bell Labs,” where different kinds of experts would unite around a shared interest in movement. Bell Labs is arguably the most successful research laboratory of all time; it has produced eight Nobel Prizes, and inventions ranging from radio astronomy to Unix and the laser. Like Bell,BLAM! would pioneer both biomedical technologies and commercial products. By developing a “self-philanthropizing ecosystem,” Krakauer believed, his lab could gain some degree of autonomy from traditionally conservative funding structures, like the National Institutes of Health.

The first problem that BLAM! has addressed as a team is stroke rehabilitation. Eight hundred thousand people in the U.S. have strokes each year; it is the No. 1 cause of long-term disability. Most cases result from clots that stop blood from flowing to part of the brain, causing tissue to die. “Picture someone standing on a hose, and the patch of grass it watered dying almost immediately,” Steve Zeiler, a neurologist and a colleague of Krakauer’s, told me. Survivors generally suffer from hemiparesis, weakness on one side of the body. We are getting better at keeping people alive, but this means that millions of Americans are now living for years in what’s called “the chronic state” of stroke: their recovery has plateaued, their insurance has often stopped covering therapy, and they are left with a moderate to severe disability.

In 2010, Krakauer received a grant from the James S. McDonnell Foundation to conduct a series of studies exploring how patients recover in the first year after a stroke. He was already well established in the worlds of motor-control and stroke research. He had discovered that a patient’s recovery was closely linked to the degree of initial impairment, a “proportional recovery rule” that had a frightening implication: if you could use early measures of impairment to make accurate predictions about a patient’s recovery three months later, what did that say about conventional physical therapy? “It doesn’t reverse the impairment,” Krakauer said.

Nick Ward, a British stroke and neurorehabilitation specialist who also works on paretic arms, told me that the current model of rehabilitative therapy for the arm is “nihilistic.” A patient lucky enough to have good insurance typically receives an hour each per day of physical, occupational, and speech therapy in the weeks following a stroke. “The movement training we are delivering is occurring at such low doses that it has no discernible impact on impairment,” Krakauer told me. “The message to patients has been: ‘Listen, your arm is really bad, your arm isn’t going to get better, we’re not going to focus on your arm,’ ” Ward said. “It’s become accepted wisdom that the arm doesn’t do well. So why bother?”

Krakauer and his team are now engaged in a clinical trial that will test a new way of delivering rehabilitation, using robotics and the video game made by Ahmad, Roy, and McNally, who make up an “arts and engineering” group within the Department of Neurology. Krakauer hopes to significantly reduce patients’ impairment, and to demonstrate that the collaborative model of BLAM! is “the way to go” for the future study and treatment of brain disease.

Reza Shadmehr, a Johns Hopkins colleague and a leader in the field of human motor-control research, told me, “He’s trying to apply things that we have developed in basic science to actually help patients. And I know that’s what you’re supposed to do, but, by God, there are very few people who really do it.”

“You bank on your reputation, in the more conventional sense, to be allowed to take these risks,” Krakauer said. “I’m cashing in my chits to do something wild.”

In 1924, Charles Sherrington, one of the founders of modern neuroscience, said, “To move things is all that mankind can do; for such the sole executant is muscle, whether in whispering a syllable or in felling a forest.” For Sherrington, a human being was a human doing.

Yet the body often seems to go about its business without us. As a result, we may be tempted to underrate the “intelligence” of the motor system. There is a deep-seated tendency in our culture, Krakauer says, to dichotomize brains and brawn, cognition and movement. But he points out that even a movement as simple as reaching for a coffee cup requires an incredibly sophisticated set of computations. “Movement is the result of decisions, and the decisions you make are reflected in movements,” Krakauer told me.

Motor skills, like Stephen Curry’s jump shot, require the acquisition and manipulation of knowledge, just like those activities we deem to be headier pursuits, such as chess and astrophysics. “Working with one’s hands is working with one’s mind,” Krakauer said, but the distinction between skill and knowledge is an ancient bias that goes back to the Greeks, for whom techne, skill, was distinct from episteme, knowledge or science.

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The Quicksort Algorithm

Quicksort is the fastest known comparison-based sorting algorithm (on average, and for a large number of elements), requiring O(n log(n)) steps. By convention, n is the number of elements to be compared and big O is a function of those elements. Quicksort is a recursive algorithm which first partitions an array according to several rules:

Pick an element, called a pivot, from the array.

Reorder the array so that all elements with values less than the pivot come before the pivot, while all elements with values greater than the pivot come after it (equal values can go either way). After this partitioning, the pivot is in its final position. This is called the partition operation.

Recursively apply the above steps to the sub-array of elements with smaller values and separately to the sub-array of elements with greater values.

Quicksort was invented by Tony Hoare and has undergone extensive analysis and scrutiny, and is known to be about twice as fast as the next fastest sorting algorithm. In the worst case, however, quicksort is a slow n² algorithm (and for quicksort, “worst case” corresponds to already sorted). (Click this link for an example of the Quicksort Algorithm written in C)

Credit: Wolfram Alpha/Wikipedia

Visualizing Growth in the U.S.: Take a look at America’s Economic Growth [831 X 1200] CLICK HERE FOR MORE MAPS! thelandofmaps.tumblr.com

What movie best represent each US state (according to subtonix)?