Featured Research

from universities, journals, and other organizations

Alzheimer's: How amyloid beta reduces plasticity related to synaptic signaling

Date:
January 3, 2010
Source:
University of California - San Diego
Summary:
The early stages of Alzheimer's disease are thought to occur at the synapse, since synapse loss is associated with memory dysfunction. Evidence suggests that amyloid beta plays an important role in early synaptic failure, but little has been understood about amyloid beta's effect on the plasticity of dendritic spines.

The early stages of Alzheimer's disease are thought to occur at the synapse, since synapse loss is associated with memory dysfunction. Evidence suggests that amyloid beta (Aβ) plays an important role in early synaptic failure, but little has been understood about Aβ's effect on the plasticity of dendritic spines.

These spines are short outgrowths of dendrites (extensions of neurons) that relay electrical impulses in the brain. A single neuron's dendrite contains hundreds of thousands of spines, providing memory storage and transmission of signals across the synapse -- the junction where such nerve impulses occur. Plasticity of these spines, or the ability to change and grow, is essential for the transmission of signaling in the brain.

Researchers led by Roberto Malinow, MD, PhD, professor of neurosciences and Shiley-Marcos Endowed Professor in Alzheimer's Disease Research at the University of California, San Diego School of Medicine, have shed more light on how Aβ's destructive effects on the brain are related to its impact on the plasticity of dentritic spines. Their study was published on December 27 in the journal Nature Neuroscience.

The researchers have shown that if Aβ is over-produced by either the pre-or post-synaptic side of the axon, it can cause destructive effects. Secondly, these effects are over a distances of about 10 microns of the neuron -- affecting thousands and thousands of synapses.

"We found that amyloid beta affects structural and not just functional, plasticity," said Malinow. "Normally, plasticity can be induced, which makes synapses stronger and bigger, but amyloid beta prevents this."

According to Malinow, it also appears that continuous release of Aβ is required to prevent plasticity. "Even a short window of 30 to 60 minutes without Aβ secretion is enough to permit plasticity to occur," he said. As Aβ's effect on the dendritic spines -- critical for memory -- had been thought to be irreversible, this shows that there is a hope of change if scientists learn how to stop the secretion of Aβ at synaptic sites."

"Our results show that the continuous production of Aβ at dendrites or axons acts locally to reduce the number and plasticity of synapses," Malinow concluded.

Additional contributors to the study include first author Wei Wei, Watson School of Biological Sciences at Cold Spring Harbor Laboratory; Louis N. Nguyen, Helmut W. Kessels and Hiroaki Hagiwara, Departments of Neurosciences and Biology at UC San Diego; and Sangram Sisodia, University of Chicago.

The study was supported by the National Institutes of Health, the Cure Alzheimer's Fund and the Leslie C. Quick Fellowship.


Story Source:

The above story is based on materials provided by University of California - San Diego. Note: Materials may be edited for content and length.


Cite This Page:

University of California - San Diego. "Alzheimer's: How amyloid beta reduces plasticity related to synaptic signaling." ScienceDaily. ScienceDaily, 3 January 2010. <www.sciencedaily.com/releases/2009/12/091228152352.htm>.
University of California - San Diego. (2010, January 3). Alzheimer's: How amyloid beta reduces plasticity related to synaptic signaling. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2009/12/091228152352.htm
University of California - San Diego. "Alzheimer's: How amyloid beta reduces plasticity related to synaptic signaling." ScienceDaily. www.sciencedaily.com/releases/2009/12/091228152352.htm (accessed October 21, 2014).

Share This



More Mind & Brain News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
Portable Breathalyzer Gets You Home Safely

Portable Breathalyzer Gets You Home Safely

Buzz60 (Oct. 21, 2014) Breeze, a portable breathalyzer, gets you home safely by instantly showing your blood alcohol content, and with one tap, lets you call an Uber, a cab or a friend from your contact list to pick you up. Sean Dowling (@SeanDowlingTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Your Birth Season Might Determine Your Temperament

Your Birth Season Might Determine Your Temperament

Newsy (Oct. 20, 2014) A new study says the season you're born in can determine your temperament — and one season has a surprising outcome. Video provided by Newsy
Powered by NewsLook.com
Movies Might Desensitize Violence For Parents, Not Just Kids

Movies Might Desensitize Violence For Parents, Not Just Kids

Newsy (Oct. 20, 2014) A study suggests that parents become desensitized to violent movies as well as children, which leads them to allow their kids to view violent films. 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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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