Featured Research

from universities, journals, and other organizations

X-linked mental retardation protein is found to mediate synaptic plasticity in hippocampus

Date:
October 20, 2011
Source:
Cold Spring Harbor Laboratory
Summary:
Scientists have solved part of a puzzle concerning the relationship between changes in the strength of synapses -- the tiny gaps across which nerve cells in the brain communicate -- and dysfunctions in neural circuits that have been linked with drug addiction, mental retardation and other cognitive disorders.

Scientists at Cold Spring Harbor Laboratory (CSHL) have solved part of a puzzle concerning the relationship between changes in the strength of synapses -- the tiny gaps across which nerve cells in the brain communicate -- and dysfunctions in neural circuits that have been linked with drug addiction, mental retardation and other cognitive disorders.

A team led by CSHL Professor Linda Van Aelst has pieced together essential steps in a signaling cascade within excitatory nerve cells that explains a key phenomenon called longterm depression, or LTD. The "depression" in question has nothing to do with the human illness with that name. Rather, it refers to a tamping-down of the strength of individual synapses -- what scientists call synaptic plasticity.

The mechanism behind LTD is called endocytosis. It involves a retraction of receptors where neurotransmitters can "dock." Van Aelst and colleagues have demonstrated how LTD works following activation of a class of receptors called group I metabotrobic glutamate receptors, or mGluRs.

It was known that longterm depression mediated by mGluRs depended in part on the rapid synthesis of specific proteins. Yet the identity of these proteins had largely remained a mystery. The CSHL scientists have now shown that locally rapid production of a protein called oligophrenin 1 (OPHN1) follows activation of group I mGluRs. OPHN1 in turn was shown to mediate LTD in hippocampal nerve cells, by interacting with yet another protein called EndophilinA2/3.

The result of this cascade of intracellular signals was dramatic: persistent removal of AMPA-type receptors at the excitatory synapse, and the onset of LTD. When rapid production of OPHN1 was blocked, mGluR-dependent LTD did not occur. These findings appear online ahead of print in the journal Neuron.

Van Aelst explained the significance of the finding. "OPHN1 has two important functions that we know about. One is early in development, after synapses have appeared in the emerging nervous system. In this phase, OPHN1 in concert with other factors stabilizes receptors at synapses, and thus is essential in maintaining the structure of these essential features of neural circuitry.

"Our new findings show another vital role for OPHN1, later in development and into maturity. We assume that in response to behavioral stimuli -- we aren't yet sure what kind -- mGluRs are activated, setting off the series of steps that we identified: rapid upregulation of OPHN1, which binds to EndophilinA2/3, which in turn mediates the long-term removal of AMPA receptors."

OPHN1 is known to be associated with X-linked mental retardation and with other cognitive and behavioral deficits. The team hypothesizes that OPHN1-related changes in plasticity such as those described in their new work may be causally related to such pathology. They are investigating this possibility in their current work.

This work was supported by grants from the National Institue of Mental Health and NAAR.


Story Source:

The above story is based on materials provided by Cold Spring Harbor Laboratory. The original article was written by Peter Tarr. Note: Materials may be edited for content and length.


Journal Reference:

  1. Nael Nadif Kasri, Akiko Nakano-Kobayashi, Linda Van Aelst. Rapid Synthesis of the X-Linked Mental Retardation Protein OPHN1 Mediates mGluR-Dependent LTD through Interaction with the Endocytic Machinery. Neuron, 2011; 72 (2): 300-315 DOI: 10.1016/j.neuron.2011.09.001

Cite This Page:

Cold Spring Harbor Laboratory. "X-linked mental retardation protein is found to mediate synaptic plasticity in hippocampus." ScienceDaily. ScienceDaily, 20 October 2011. <www.sciencedaily.com/releases/2011/10/111019212248.htm>.
Cold Spring Harbor Laboratory. (2011, October 20). X-linked mental retardation protein is found to mediate synaptic plasticity in hippocampus. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2011/10/111019212248.htm
Cold Spring Harbor Laboratory. "X-linked mental retardation protein is found to mediate synaptic plasticity in hippocampus." ScienceDaily. www.sciencedaily.com/releases/2011/10/111019212248.htm (accessed September 2, 2014).

Share This




More Mind & Brain News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Can You Train Your Brain To Eat Healthy?

Can You Train Your Brain To Eat Healthy?

Newsy (Sep. 1, 2014) New research says if you condition yourself to eat healthy foods, eventually you'll crave them instead of junk food. Video provided by Newsy
Powered by NewsLook.com
Coffee Then Napping: The (New) Key To Alertness

Coffee Then Napping: The (New) Key To Alertness

Newsy (Aug. 30, 2014) Researchers say having a cup of coffee then taking a nap is more effective than a nap or coffee alone. Video provided by Newsy
Powered by NewsLook.com
Young Entrepreneurs Get $100,000, If They Quit School

Young Entrepreneurs Get $100,000, If They Quit School

AFP (Aug. 29, 2014) Twenty college-age students are getting 100,000 dollars from a Silicon Valley leader and a chance to live in San Francisco in order to work on the start-up project of their dreams, but they have to quit school first. Duration: 02:20 Video provided by AFP
Powered by NewsLook.com
Baby Babbling Might Lead To Faster Language Development

Baby Babbling Might Lead To Faster Language Development

Newsy (Aug. 29, 2014) A new study suggests babies develop language skills more quickly if their parents imitate the babies' sounds and expressions and talk to them often. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins