Navigation Links
X-linked mental retardation protein is found to mediate synaptic plasticity in hippocampus
Date:10/19/2011

Cold Spring Harbor, NY 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 today 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.


'/>"/>

Contact: Peter Tarr
tarr@cshl.edu
516-367-8455
Cold Spring Harbor Laboratory
Source:Eurekalert

Related biology news :

1. Polar bears ill from accumulated environmental toxins
2. Can indigenous peoples be relied on to gather reliable environmental data?
3. New data-mining effort launched to study mental disorders
4. Seed time-capsule will aid study of plant evolution amid environmental change
5. Decline and recovery of coral reefs linked to 700 years of human and environmental activity
6. Control gene for developmental timing discovered
7. JoVE grants developing countries access to experimental videos
8. Fast-evolving genes control developmental differences in social insects
9. EPA grants help Wayne State researchers stave off Great Lakes environmental invaders
10. Cells derived from pluripotent stem cells are developmentally immature
11. Genomewide mapping reveals developmental and environmental impacts
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/20/2016)... May 20, 2016  VoiceIt is excited to ... VoicePass. By working together, VoiceIt and ... VoiceIt and VoicePass take slightly different approaches to ... both security and usability. ... this new partnership. "This marketing and ...
(Date:5/12/2016)... May 12, 2016 WearablesResearch.com , a ... the overview results from the Q1 wave of its ... wave was consumers, receptivity to a program where they ... a health insurance company. "We were surprised ... says Michael LaColla , CEO of Troubadour Research, ...
(Date:5/3/2016)...  Neurotechnology, a provider of high-precision biometric identification ... Identification System (ABIS) , a complete system for ... can process multiple complex biometric transactions with high ... face or iris biometrics. It leverages the core ... MegaMatcher Accelerator , which have been used in ...
Breaking Biology News(10 mins):
(Date:5/19/2016)... MAPLE RIDGE, British Columbia , May 19, ... of AdvanTec Global Innovations Inc. (AGI), based out ... recently added Greenlane Biogas Ltd. to its ... a 2-year contract manufacturing agreement. AFS along with ... Bending Technologies (ABT) is a vertically integrated industrial ...
(Date:5/19/2016)... , May 19, 2016 ... and (OTC PINK: RGBPP) announced today initiation of ... first cord blood based cancer immunotherapeutic product leveraging ... application, Regen described a generation of cord blood ... by gene silencing.  The product in development will ...
(Date:5/18/2016)... ... May 18, 2016 , ... Shimadzu Scientific Instruments ... University of Toledo. This two-day camp will take place annually starting June 2016. ... of pharmaceutical sciences in preparation for a university academic program. , The ...
(Date:5/18/2016)... ... May 18, 2016 , ... Every day, more ... of asthma complications.* Costing more than $56 billion in direct costs annually, asthma ... “For too many, the suffering associated with uncontrolled asthma can be overwhelmingly disproportionate ...
Breaking Biology Technology: