Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The dendritic branch is the preferred integrative unit for protein synthesis-dependent LTP

19.01.2011
Neuroscientists have uncovered why relatively minor details of an episode are sometimes inexplicably linked to long-term memories.

Neuroscientists at MIT's Picower Institute of Learning and Memory have uncovered why relatively minor details of an episode are sometimes inexplicably linked to long-term memories. The work, slated to appear in the Jan. 13, 2011 issue of Neuron, explains at a molecular level for the first time.

"Our finding explains, at least partially, why seemingly irrelevant information like the color of the shirt of an important person is remembered as vividly as more significant information such as the person's impressive remark when you recall an episode of meeting this person," said co-author Susumu Tonegawa, Picower Professor of Biology and Neuroscience and Director of the RIKEN-MIT Center for Neural Circuit Genetics.

The data also showed that irrelevant information that follows the relevant event rather than precedes it is more likely to be integrated into long-term memory.

Shaping a memory

One theory holds that memory traces or fragments are distributed throughout the brain as biophysical or biochemical changes called engrams. The exact mechanism underlying engrams is not well understood.

MIT neuroscientists Arvind Govindarajan, assistant director of the RIKEN/MIT Center for Neural Circuit Genetics; Picower Institute postdoctoral associate Inbal Israely; and technical associate Shu-Ying Huang; and Susumu Tonegawa looked at single neurons to explore how memories are created and stored in the brain.

Previous research has focused on the role of synapses—the connections through which neurons communicate. An individual synapse is thought to be the minimum unit necessary to establish a memory engram.

Instead of looking at individual synapses, the MIT study explored neurons' branch-like networks of dendrites and the multiple synapses within them.

Boosting the signal

In response to external stimuli, dendritic spines in the cerebral cortex undergo structural remodeling, getting larger in response to repeated activity within the brain. This remodeling is thought to underlie all learning and memory.

Neurons sprout branch-like dendrites that transmit incoming electrochemical stimulation to the trunk-like cell body. Synapses located at various points throughout the dendritic arbor act as signal amplifiers for the dendrites, which play a critical role in integrating these synaptic inputs and determining the extent to which the neuron acts on incoming signals.

The MIT researchers found that a memory of a seemingly irrelevant detail—the kind of detail that would normally be relegated to a short-term memory--may accompany a long-term memory if two synapses on a single dendritic arbor are stimulated within an hour and a half of each other.

"A synapse that received a weak stimulation, the kind that would normally accompany a short-term memory, will express a correlate of a long-term memory if two synapses on a single dendritic branch were involved in a similar time frame," Govindarajan said.

This occurs because the weakly stimulated synapse can steal or hitchhike on a set of proteins synthesized at or near the strongly stimulated synapse. These proteins are necessary for the enlargement of a dendritic spine that allows the establishment of a long-term memory.

"Not all irrelevant information is recalled, because some of it did not stimulate the synapses of the dendritic branch that happens to contain the strongly stimulated synapse," Israely said. This work was supported by RIKEN, Howard Hughes Medical Institute and the National Institutes of Health.

By Deborah Halber

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

More articles from Life Sciences:

nachricht Brought to light – chromobodies reveal changes in endogenous protein concentration in living cells
21.09.2018 | NMI Naturwissenschaftliches und Medizinisches Institut an der Universität Tübingen

nachricht A one-way street for salt
21.09.2018 | Julius-Maximilians-Universität Würzburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists present new observations to understand the phase transition in quantum chromodynamics

The building blocks of matter in our universe were formed in the first 10 microseconds of its existence, according to the currently accepted scientific picture. After the Big Bang about 13.7 billion years ago, matter consisted mainly of quarks and gluons, two types of elementary particles whose interactions are governed by quantum chromodynamics (QCD), the theory of strong interaction. In the early universe, these particles moved (nearly) freely in a quark-gluon plasma.

This is a joint press release of University Muenster and Heidelberg as well as the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt.

Then, in a phase transition, they combined and formed hadrons, among them the building blocks of atomic nuclei, protons and neutrons. In the current issue of...

Im Focus: Patented nanostructure for solar cells: Rough optics, smooth surface

Thin-film solar cells made of crystalline silicon are inexpensive and achieve efficiencies of a good 14 percent. However, they could do even better if their shiny surfaces reflected less light. A team led by Prof. Christiane Becker from the Helmholtz-Zentrum Berlin (HZB) has now patented a sophisticated new solution to this problem.

"It is not enough simply to bring more light into the cell," says Christiane Becker. Such surface structures can even ultimately reduce the efficiency by...

Im Focus: New soft coral species discovered in Panama

A study in the journal Bulletin of Marine Science describes a new, blood-red species of octocoral found in Panama. The species in the genus Thesea was discovered in the threatened low-light reef environment on Hannibal Bank, 60 kilometers off mainland Pacific Panama, by researchers at the Smithsonian Tropical Research Institute in Panama (STRI) and the Centro de Investigación en Ciencias del Mar y Limnología (CIMAR) at the University of Costa Rica.

Scientists established the new species, Thesea dalioi, by comparing its physical traits, such as branch thickness and the bright red colony color, with the...

Im Focus: New devices based on rust could reduce excess heat in computers

Physicists explore long-distance information transmission in antiferromagnetic iron oxide

Scientists have succeeded in observing the first long-distance transfer of information in a magnetic group of materials known as antiferromagnets.

Im Focus: Finding Nemo's genes

An international team of researchers has mapped Nemo's genome

An international team of researchers has mapped Nemo's genome, providing the research community with an invaluable resource to decode the response of fish to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

One of the world’s most prominent strategic forums for global health held in Berlin in October 2018

03.09.2018 | Event News

4th Intelligent Materials - European Symposium on Intelligent Materials

27.08.2018 | Event News

 
Latest News

Astrophysicists measure precise rotation pattern of sun-like stars for the first time

21.09.2018 | Physics and Astronomy

Brought to light – chromobodies reveal changes in endogenous protein concentration in living cells

21.09.2018 | Life Sciences

"Boston calling": TU Berlin and the Weizenbaum Institute organize a conference in USA

21.09.2018 | Event News

VideoLinks
Science & Research
Overview of more VideoLinks >>>