Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Hopkins researchers discover how brain protein might control memory

Researchers at Johns Hopkins have figured out how one particular protein contributes to long-term memory and helps the brain remember things longer than an hour or two. The findings are reported in two papers in the Nov. 9 issue of Neuron.

The protein, called Arc, has been implicated in memory-linked behaviors ranging from song learning in birds to rodents being aware of 3-D space. In people, Arc may be one culprit behind certain long-term memory-based behaviors like drug addiction, the researchers say.

"We think Arc controls how brain cells learn and associate behaviors and remember them over a long period of time," says Paul F. Worley, M.D., professor of neuroscience and neurology at Hopkins and director of both studies. "For example, the person who quits smoking can wean himself from cravings at home, at work or outside. But if you put him in a bar with a drink in his hand, his brain remembers that former association and suddenly the craving returns. These types of long-term associations are memories wired in your brain."

Years ago, Worley and his colleagues, studying laboratory rats, found that their brains made lots of Arc protein while the animals were awake and active. In fact, it has been long known that stimulating individual nerve cells - by an act as simple as exploring new environs, for example - causes the cells to make more Arc protein almost immediately. "Arc is an instant and reliable readout for active cells in the brain," says Worley. But although scientists knew that active cells were making copious amounts of Arc, no one knew exactly what Arc was doing in those cells until now.

To figure out what Arc was doing, the Hopkins team looked for what other proteins Arc "plays" with. Using Arc protein as bait, they went on a molecular fishing expedition in a pond filled with other proteins normally found in the brain and hooked two known to be involved in transporting materials into and out of cells.

"Moving things in and out of cells is critical for normal brain cell function. We were extremely excited that Arc might somehow be involved in this transport because it links transport to memory formation," says Worley. "This brings us one step closer to understanding how the brain saves memories."

According to Worley, memories form when nerve cells connect and "talk" to other nerve cells. It's thought that the stronger these connections are, the stronger the memory.

Like the childhood game called Telephone, where one person taps her neighbor and whispers a message that is passed on in similar fashion to the next person in line, nerve cells connect and "talk" to each other by relaying messages - usually by passing small chemicals - from cell to cell.

When nerve cells connect with each other in the brain, one cell releases chemicals into the space between it and its neighbor. The neighboring cell has protein receptors on its surface that capture the released chemicals. The cell that captures these chemicals then swallows up the receptor-chemical complexes, removing the receptors from the cell's surface. The more receptors present, according to Worley, the stronger the connection between the two cells. New receptors constantly replace the swallowed-up ones.

The two proteins that came out of the Arc fishing expedition - known as dynamin and endophilin - previously were known to be critical for this swallowing action. And, it turns out that Arc controls these two proteins and therefore controls how often cells swallow receptors from their surfaces.

When the researchers altered Arc so that it was unable to bind these two proteins, cells were unable to "swallow" and wound up with more receptors than normal on their surfaces. Adding more Arc to cells caused the opposite to happen; the cells hyperactively swallowed up too many receptors, leaving few at the surface.

Unfortunately, it's possible to over-excite a cell to death, says Worley, and if the excitation controls come off, the strength of long-term memory is altered.

So what does Arc's control over brain cell receptors mean for our ability to remember where we put the car keys? "We know that animals lacking Arc live only in the here and now. They learn fine in the short term, but tomorrow they will need to relearn everything," says Worley. And in the case of long-term memories that are better forgotten, such as that cigarette craving while sitting in a bar, a better understanding of how these memories form promises hope that there might be a way in the future to forget them entirely.

Audrey Huang | EurekAlert!
Further information:

Further reports about: ARC Control Protein Receptors Researchers Worley chemicals memories

More articles from Life Sciences:

nachricht Gene therapy shows promise for treating Niemann-Pick disease type C1
27.10.2016 | NIH/National Human Genome Research Institute

nachricht 'Neighbor maps' reveal the genome's 3-D shape
27.10.2016 | International School of Advanced Studies (SISSA)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

How nanoscience will improve our health and lives in the coming years

27.10.2016 | Materials Sciences

OU-led team discovers rare, newborn tri-star system using ALMA

27.10.2016 | Physics and Astronomy

'Neighbor maps' reveal the genome's 3-D shape

27.10.2016 | Life Sciences

More VideoLinks >>>