Featured Research

from universities, journals, and other organizations

Alteration Of Brain Protein Regulates Learning

Date:
August 22, 2005
Source:
UT Southwestern Medical Center
Summary:
Researchers at UT Southwestern Medical Center have identified a biochemical switch that affects how neurons fire in a part of the brain associated with learning, findings that may aid in understanding schizophrenia and Alzheimer's disease.

DALLAS - Aug. 17, 2005 - Researchers at UT SouthwesternMedical Center have identified a biochemical switch that affects howneurons fire in a part of the brain associated with learning, findingsthat may aid in understanding schizophrenia and Alzheimer's disease.

Related Articles


Theresearch sheds new light on the action of reelin, a protein known to beimportant in the nervous system. During development, reelin sends cuesto migrating neurons, telling them where they're supposed to go. Inadult mice, reelin has recently been implicated in the formation ofmemories, and reduced production of reelin has been associated withschizophrenia in humans.

In a report published in the Aug.18issue of the journal Neuron, the researchers, including Dr. UweBeffert, postdoctoral researcher in molecular genetics and lead authorof the study, and Dr. Joachim Herz, professor of molecular genetics anda member of the Center for Basic Neuroscience at UT Southwestern andthe paper's senior author, studied an area of the brain called thehippocampus, which is important for learning. The researchers focusedon the interaction of reelin and two other molecules, Apoer2 and theNMDA receptor.

In the nervous system the NMDA receptor isembedded in the membrane of synapses - gaps between nerve cells - whereit is involved in receiving signals from other nerve cells. Apoer2 isanother receptor which is associated with the NMDA receptor. Whenreelin encounters the cell, it attaches to Apoer2, which then booststhe activity of the NMDA receptor by promoting a chemical modificationof the part of the NMDA receptor inside the cell. The result of thismodification is that signals being received by the nerve cell areamplified - and better reception means better learning.

Thistransition in the primary function of Apoer2, from guiding neurons inthe embryonic brain to regulating synaptic signaling, occurs around thetime of birth. A small string of amino acids, the building blocks ofproteins, gets added near one end of Apoer2 and is essential for thisnew function. Adding the new amino acids is similar to cutting a rope,splicing in a short portion, and lashing the ends in place.

Thislonger form of Apoer2 is necessary for reelin to act upon the NMDAreceptor, Dr. Herz and his colleagues found. When reelin binds to thelonger Apoer2, the NMDA receptor alters its structure and actions,resulting in the strengthening of the signals the nerve cells receive.

Whenthe researchers created mutant mice in which Apoer2 was missing thespliced portion, they found that the mice had difficulties withlearning and memory. They were slow to learn where a hidden platformwas in murky water, among other tasks, and when the electrical activityof neurons was measured in the hippocampus of these mice there was nolonger any detectable reaction to reelin.

Thus, the extra stringof amino acids in Apoer2 seems to work like a switch that patches thereelin signal through to the NMDA receptor and, thereby, plays acentral role for learning and memory in the whole animal.

Inaddition to reelin, Apoer2 binds to a protein called ApoE. One form ofthis molecule, called ApoE4, has been shown to substantially increasethe risk of Alzheimer's disease in older people. Understanding howApoE4 functions in the brain and interacts with ApoE receptors, such asApoer2, is critical for gaining further insight into the mysteriousmechanisms that cause this debilitating neurodegenerative disease, Dr.Herz said. The loss of synapses that occurs in Alzheimer's disease isthe primary cause for the dementia in the afflicted patients.

"Our findings put ApoE receptors at the heart of the matter," said Dr. Herz.

OtherUT Southwestern researchers involved in the study were Dr. RobertHammer, professor of biochemistry; Dr. Wei-Ping Li, assistant professorof cell biology; Andre Durudas, student research assistant in internalmedicine; and Irene Masiulis, student research assistant in biophysicsand molecular genetics. Researchers from Vanderbilt University, BaylorCollege of Medicine and the Center for Neuroscience in Freiburg,Germany, also participated.

The work was supported by theNational Institutes of Health, the Alzheimer's Association, theWolfgang Paul Award of the Alexander von Humboldt Foundation, the PerotFoundation, the American Health Assistance Foundation, the HumanFrontier Science Program, the Canadian Institutes of Health Researchand the Deutsche Forschungsgemeinschaft.


Story Source:

The above story is based on materials provided by UT Southwestern Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

UT Southwestern Medical Center. "Alteration Of Brain Protein Regulates Learning." ScienceDaily. ScienceDaily, 22 August 2005. <www.sciencedaily.com/releases/2005/08/050821234724.htm>.
UT Southwestern Medical Center. (2005, August 22). Alteration Of Brain Protein Regulates Learning. ScienceDaily. Retrieved October 30, 2014 from www.sciencedaily.com/releases/2005/08/050821234724.htm
UT Southwestern Medical Center. "Alteration Of Brain Protein Regulates Learning." ScienceDaily. www.sciencedaily.com/releases/2005/08/050821234724.htm (accessed October 30, 2014).

Share This



More Health & Medicine News

Thursday, October 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Mind-Controlled Prosthetic Arm Restores Amputee Dexterity

Reuters - Innovations Video Online (Oct. 29, 2014) A Swedish amputee who became the first person to ever receive a brain controlled prosthetic arm is able to manipulate and handle delicate objects with an unprecedented level of dexterity. The device is connected directly to his bone, nerves and muscles, giving him the ability to control it with his thoughts. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Google To Use Nanoparticles, Wearables To Detect Disease

Google To Use Nanoparticles, Wearables To Detect Disease

Newsy (Oct. 29, 2014) Google X wants to improve modern medicine with nanoparticles and a wearable device. It's all an attempt to tackle disease detection and prevention. Video provided by Newsy
Powered by NewsLook.com
Can Drinking Milk Lead To Early Death?

Can Drinking Milk Lead To Early Death?

Newsy (Oct. 29, 2014) Researchers in Sweden released a study showing heavy milk drinkers face an increased mortality risk from a variety of causes. Video provided by Newsy
Powered by NewsLook.com
Obama: The US Will Not 'run and Hide' From Ebola

Obama: The US Will Not 'run and Hide' From Ebola

AP (Oct. 29, 2014) Surrounded by health care workers in the White House East Room, President Barack Obama said the U.S. will likely see additional Ebola cases in the weeks ahead. But he said the nation can't seal itself off in the fight against the disease. (Oct. 29) Video provided by AP
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