Navigation Links
MIT neuroscientists explain 'Proustian effect' of small details attached to big memories

CAMBRIDGE, Mass. 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 is slated to appear in the Jan. 13 issue of Neuron.

"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 Tonegawa looked at single neurons to explore how memories are created and stored in the brain.

Previous research has focused on the role of synapsesthe 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

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

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 learning and memory.

The MIT researchers found that a memory of a seemingly irrelevant detailthe 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.


Contact: Jessica Holmes
Massachusetts Institute of Technology

Related medicine news :

1. Ion channel responsible for pain identified by UB neuroscientists
2. Neuroscientists reveal new links that regulate brain electrical activity
3. Yo-yo effect of slimming diets explained
4. Scientists explain link between chlamydia and ectopic pregnancy
5. VCU findings may help explain some major clinical symptoms of preeclampsia
6. Brochures explaining new health care law to patients available free in English and Spanish
7. Protein Differences May Explain Long-Term HIV Control
8. Wild Scottish sheep could help explain differences in immunity
9. Brains Pleasure Chemical May Explain Mens Higher Alcoholism Rate
10. Insurance, Income Dont Explain Race Gap in Breast Cancer Care
11. Insurance and socioeconomic status do not explain racial disparities in breast cancer care
Post Your Comments:
(Date:11/27/2015)... ... November 27, 2015 , ... According to an ... changing the way that they are handling security in light of the recent terrorist ... presence in an attempt to stop an attack from reaching U.S. soil. Especially around ...
(Date:11/27/2015)... (PRWEB) , ... November 27, 2015 , ... Lizzie’s Lice ... The company is offering customers 10% off of their purchase of lice treatment product. ... at full price. According to a company spokesperson. “Finding lice is a sure way ...
(Date:11/27/2015)... DE (PRWEB) , ... November 27, 2015 , ... ... member of the well-respected Microsoft Dynamics SL User Group (MSDSLUG). Recognized as Microsoft’s ... an independent group of Microsoft Dynamics SL software users, partners, industry experts and ...
(Date:11/27/2015)... ... November 27, 2015 , ... ... most successful and prominent nonprofit healthcare organizations in the country. They have overseen ... various organizations, and helped advance the healthcare industry as a whole through their ...
(Date:11/26/2015)... Vegas, NV (PRWEB) , ... November 26, 2015 , ... ... shopping strategy. Many customers choose to buy during the Black Friday and Cyber ... gifts. Shoppers don’t need to search the Internet high and low to find the ...
Breaking Medicine News(10 mins):
(Date:11/25/2015)... Nov. 25, 2015 On Tuesday, November ... bellwether trial against Wright Medical Technology, Inc. for ... Conserve metal-on-metal hip implant device, awarded $11 million ... two week trial and three days of deliberations, ... device was defectively designed and unreasonably dangerous, and ...
(Date:11/25/2015)... Nov. 25, 2015  Henry Schein, Inc., the world,s ... office-based dental, medical and animal health practitioners, will unveil ... Henry Schein ConnectDental® Pavilion , which brings together ... open solutions designed to help any practice or laboratory ... for a schedule of experts appearing at the ...
(Date:11/25/2015)... plc (NYSE: AGN ) today announced that it has ... Attorney General,s Office to end the litigation under ... the Attorney General over the decision of Forest Laboratories, Inc., ... now generic version of memantine immediate release tablets.  Under the ... counterclaims against New York , and has ...
Breaking Medicine Technology: