2012年12月31日星期一

ScienceDaily: Latest Science News: Direct evidence for receptor's role in synapse development

ScienceDaily: Latest Science News

Breaking science news and articles on global warming, extrasolar planets, stem cells, bird flu, autism, nanotechnology, dinosaurs, evolution -- the latest discoveries in astronomy, anthropology, biology, chemistry, climate and environment, computers, engineering, health and medicine, math, physics, psychology, technology, and more -- from the world's leading universities and research organizations.

Direct evidence for receptor's role in synapse development
http://feeds.sciencedaily.com/~r/sciencedaily/~3/Ilph_sjEjzg/121231161049.htm
Dec 31st 2012, 21:10

Dec. 31, 2012 — Jackson Laboratory researchers led by Associate Professor Zhong-wei Zhang, Ph.D., have provided direct evidence that a specific neurotransmitter receptor is vital to the process of pruning synapses in the brains of newborn mammals.

Faulty pruning at this early developmental stage is implicated in autism-spectrum disorders and schizophrenia. The definitive evidence for N-methyl-D-aspartate receptor (NMDAR) in pruning has eluded researchers until now, but in research published in the Proceedings of the National Academy of Sciences, Zhang's lab had serendipitous help in the form of a mouse model containing brain cells lacking NMDAR side-by-side with cells containing the receptor.
Soon after birth, mammals' brains undergo significant development and change. Initially, large numbers of synapses form between neurons. Then, in response to stimuli, the synaptic connections are refined -- some synapses are strengthened and others eliminated, or pruned.
In most synapses, glutamate serves as the neurotransmitter, and NMDAR, a major type of post-synaptic glutamate receptor, was previously known to play an important role in neural circuit development. Previous research has implicated the importance of NMDARs in pruning, but it remained unclear whether they played a direct or indirect role.
Zhang and colleagues focused on the thalamus, a brain region where synapse pruning and strengthening can be monitored and quantified with relative ease. They got unexpected help when they realized the mouse model they were using had thalamus cells lacking NMDARs right next to cells with normal NMDAR levels.
The researchers showed that the refinement process was disrupted in the absence of NMDARs. At the same time, neighboring neurons with the receptors proceeded through normal synaptic strengthening and pruning, clearly establishing the necessity of NMDARs in postsynaptic neurons for synaptic refinement.
"Whenever I give a talk or meet colleagues," Zhang says, "the first question that comes up is whether the NMDA receptor is important. It's good that this is now settled definitively."
There has been extensive research into synaptic strengthening, and most of these studies indicate that the presence of NMDARs may support the recruitment of larger numbers of another kind of glutamate receptor to strengthen the synaptic connections. How NMDARs regulate the pruning process remains largely unknown, however.
The Jackson Laboratory is an independent, nonprofit biomedical research institution based in Bar Harbor, Maine, with a facility in Sacramento, Calif., and a new genomic medicine institute in Farmington, Conn. It employs a total staff of more than 1,400. Its mission is to discover precise genomic solutions for disease and empower the global biomedical community in the shared quest to improve human health.
Share this story on Facebook, Twitter, and Google:

Other social bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by Jackson Laboratory.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:
Zhong-Wei Zhang, Matthew Peterson, Hong Liu. Essential role of postsynaptic NMDA receptors in developmental refinement of excitatory synapses. Proceedings of the National Academy of Sciences, 2012; DOI: 10.1073/pnas.1212971110



Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.
This entry passed through the Full-Text RSS service — if this is your content and you're reading it on someone else's site, please read the FAQ at fivefilters.org/content-only/faq.php#publishers. Five Filters recommends: Gaza Blitz - Turmoil And Tragicomedy At The BBC.



You are receiving this email because you subscribed to this feed at http://blogtrottr.com

If you no longer wish to receive these emails, you can unsubscribe here:
http://blogtrottr.com/unsubscribe/cz0/tSbHWJ

没有评论:

发表评论

博客归档