Navigation Links
Eliminating useless information important to learning, making new memories
Date:1/9/2013

AUGUSTA, Ga. As we age, it just may be the ability to filter and eliminate old information rather than take in the new stuff - that makes it harder to learn, scientists report.

"When you are young, your brain is able to strengthen certain connections and weaken certain connections to make new memories," said Dr. Joe Z. Tsien, neuroscientist at the Medical College of Georgia at Georgia Regents University and Co-Director of the GRU Brain & Behavior Discovery Institute.

It's that critical weakening that appears hampered in the older brain, according to a study in the journal Scientific Reports.

The NMDA receptor in the brain's hippocampus is like a switch for regulating learning and memory, working through subunits called NR2A and NR2B. NR2B is expressed in higher percentages in children, enabling neurons to talk a fraction of a second longer; make stronger bonds, called synapses; and optimize learning and memory. This formation of strong bonds is called long-term potentiation. The ratio shifts after puberty, so there is more NR2A and slightly reduced communication time between neurons.

When Tsien and his colleagues genetically modified mice that mimic the adult ratio more NR2A, less NR2B they were surprised to find the rodents were still good at making strong connections and short-term memories but had an impaired ability to weaken existing connections, called long-term depression, and to make new long-term memories as a result. It's called information sculpting and adult ratios of NMDA receptor subunits don't appear to be very good at it.

"If you only make synapses stronger and never get rid of the noise or less useful information then it's a problem," said Tsien, the study's corresponding author. While each neuron averages 3,000 synapses, the relentless onslaught of information and experiences necessitates some selective whittling. Insufficient sculpting, at least in their mouse, meant a reduced ability to remember things short-term like the ticket number at a fast-food restaurant and long-term like remembering a favorite menu item at that restaurant. Both are impacted in Alzheimer's and age-related dementia.

All long-term depression was not lost in the mice, rather just response to the specific electrical stimulation levels that should induce weakening of the synapse. Tsien expected to find the opposite: that long-term potentiation was weak and so was the ability to learn and make new memories. "What is abnormal is the ability to weaken existing connectivity."

Acknowledging the leap, this impaired ability could also help explain why adults can't learn a new language without their old accent and why older people tend to be more stuck in their ways, the memory researcher said.

"We know we lose the ability to perfectly speak a foreign language if we learn than language after the onset of sexual maturity. I can learn English but my Chinese accent is very difficult to get rid of. The question is why," Tsien said.

Tsien and his colleagues already have learned what happens when NR2B is overexpressed. He and East China Normal University researchers announced in 2009 the development of Hobbie-J, a smarter than average rat. A decade earlier, Tsien reported in the journal Nature the development of a smart mouse dubbed Doogie using the same techniques to over-express the NR2B gene in the hippocampus.

Doogie, Hobbie-J and their descendants have maintained superior memory as they age. Now Tsien is interested in following the NR2A over-expressing mouse to see what happens.


'/>"/>

Contact: Toni Baker
tbaker@gru.edu
706-721-4421
Georgia Health Sciences University
Source:Eurekalert  

Related biology news :

1. An error-eliminating fix overcomes big problem in 3rd-gen genome sequencing
2. A foot in the door to genetic information
3. Expedition to undersea mountain yields new information about sub-seafloor structure
4. New databases harvest a rich bounty of information on crop plant metabolism
5. Global Information Inc. Announces Discounted Conference Registration For Bio-IT World Asia and Biodetection Technologies 2012
6. New genetic bar code technique establishes ability to derive DNA information from RNA
7. Geographic information systems demonstrate links between health and location
8. New Biotech and Pharmaceutical Market Research from Global Information Inc Forecasts Strong Growth Coming Out of Recession
9. Copernicus Award 2012 for German-Polish collaboration in business information systems
10. 2012 Forecast for US Molecular Diagnostics Market Now Available From Global Information Inc.
11. Doubling the information from the double helix
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Eliminating useless information important to learning, making new memories
(Date:6/23/2017)... and ITHACA, N.Y. , June 23, ... University, a leader in dairy research, today announced a ... to help reduce the chances that the global milk ... of this dairy project, Cornell University has become the ... the Food Supply Chain, a food safety initiative that ...
(Date:5/23/2017)... 2017  Hunova, the first robotic gym for the rehabilitation and functional ... in Genoa, Italy . The first 30 robots will ... USA . The technology was developed and patented at ... IIT spin-off Movendo Technology thanks to a 10 million euro investment from ... click: ...
(Date:5/16/2017)... 16, 2017   Bridge Patient Portal , ... MD EMR Systems , an electronic medical ... GE, have established a partnership to build an ... the GE Centricity™ products, including Centricity Practice Solution ... These new integrations will allow healthcare delivery ...
Breaking Biology News(10 mins):
(Date:8/16/2017)... Ca (PRWEB) , ... August 16, 2017 , ... ... by changing into a different cell type. Many treatments for specific cancers, such ... prominent example of targeted treatment is androgen deprivation therapy for advanced prostate cancer. ...
(Date:8/16/2017)... OH (PRWEB) , ... August 16, 2017 , ... ... a beneficial microbe delivery system, announced it has secured $2M in funding from ... Queen City Angels, Carmen Innovations, and SVG Thrive Fund. With this investment, 3Bar ...
(Date:8/16/2017)... of the Inc. 5000 features a now-familiar name: BioPoint ( http://biopointinc.com/ ), ... for the third year in a row. Now in its 36th edition, ... set of quantitative metrics. In addition, BioPoint was also named to the ... Bay State . ... ...
(Date:8/15/2017)... STANFORD, Calif. , Aug. 15, 2017 After spending ... resources and support with crowdsourced data collection, GeneFo now offers this ... interested in aligning and amplifying support, adherence, and data collection vis ... with medical foundations mark the successful launch of this offer. ... GeneFo ...
Breaking Biology Technology: