Featured Research

from universities, journals, and other organizations

Making Memories That Last A Lifetime

Date:
March 15, 2007
Source:
Cell Press
Summary:
Neurobiologists have discovered a mechanism by which the constantly changing brain retains memories -- from that dog bite to that first kiss. They have found that the brain co-opts the same machinery by which cells stably alter their genes to specialize during embryonic development.

Neurobiologists have discovered a mechanism by which the constantly changing brain retains memories--from that dog bite to that first kiss. They have found that the brain co-opts the same machinery by which cells stably alter their genes to specialize during embryonic development.

Related Articles


Courtney Miller and David Sweatt's studies aimed at exploring whether a process called DNA methylation plays a role in forming memories. In this process, molecules called methyl groups are attached to genes, which switches them off. Conversely, lack of methyl groups enables the genes to remain activated.

Cells use methylation during embryonic development to selectively deactivate genes to enable the cells to specialize into different types as the embryo develops. Such regulation is dubbed "epigenetic," since it constitutes a layer of genetic control beyond the regulation inherent in the structure of genes themselves.

Methylation causes a permanent change in gene activity during development. So, while previous studies by Sweatt and others had hinted that the methylation mechanism remains active in adult brains, researchers had generally believed that methylation would not constitute a mechanism for long-term establishment of memories. However, as misregulation of DNA methylation occurs in some brain disorders like schizophrenia and forms of mental retardation, Miller and Sweatt designed experiments to test whether methylation specifically regulates memory formation.

In their experiments, the researchers conditioned fearful memories in rats by giving the animals mild shocks when they were in a specific training chamber. The researchers could then test whether the rats remembered the conditioning by observing whether they froze when placed in the chamber.

Using drugs that inhibit methylation, the researchers showed that methylation was necessary for rats to form such memories. Particularly importantly, the researchers found that the level of methylation directly controlled the activity of genes known to either suppress or promote memory formation. The memory suppressor gene they studied is called protein phosphatase 1, and the memory-promoting gene is called reelin.

"To our knowledge, this study is the first to present evidence that DNA methylation, once thought to be a static process after cellular differentiation, is not only dynamically regulated in the adult nervous system but also plays an integral role in memory formation," concluded Miller and Sweatt. They wrote that their findings indicate that DNA methylation has been co-opted by the central nervous system as a "crucial step" in regulating gene activity involved in memory formation.

What's more, they noted, abnormal epigenetic regulation has been seen in cancer, some types of autism, and schizophrenia. Thus, they said their findings could aid in basic understanding of epigenetic mechanisms that underlie those disorders.

"The findings presented here may provide an important and relevant piece of data to the schizophrenia field, as they provide evidence that reelin methylation is subject to modulation in response to experience and environmental stimuli," wrote Miller and Sweatt.

More broadly, they wrote, their findings "indicate the importance of dynamic regulation of DNA methylation in behavioral changes brought about by the perception of environmental stimuli."

The researchers include Courtney A. Miller and J. David Sweatt of University of Alabama at Birmingham in Birmingham, AL.

This work was supported by the NIMH, NINDS, American Health Assistance Foundation, and the Evelyn F. McKnight Brain Research Foundation. C.A.M. is a Civitan Emerging Scholar.

Reference: Miller et al.: "Covalent Modification of DNA Regulates Memory Formation." Publishing in Neuron 53, 857--869, March 15, 2007. DOI 10.1016/j.neuron.2007.02.022.


Story Source:

The above story is based on materials provided by Cell Press. Note: Materials may be edited for content and length.


Cite This Page:

Cell Press. "Making Memories That Last A Lifetime." ScienceDaily. ScienceDaily, 15 March 2007. <www.sciencedaily.com/releases/2007/03/070314134821.htm>.
Cell Press. (2007, March 15). Making Memories That Last A Lifetime. ScienceDaily. Retrieved February 27, 2015 from www.sciencedaily.com/releases/2007/03/070314134821.htm
Cell Press. "Making Memories That Last A Lifetime." ScienceDaily. www.sciencedaily.com/releases/2007/03/070314134821.htm (accessed February 27, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Friday, February 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sleeping Too Much Or Too Little Might Increase Stroke Risk

Sleeping Too Much Or Too Little Might Increase Stroke Risk

Newsy (Feb. 26, 2015) People who sleep more than eight hours per night are 45 percent more likely to have a stroke, according to a University of Cambridge study. Video provided by Newsy
Powered by NewsLook.com
Mayor Says District of Columbia to Go Ahead With Pot Legalization

Mayor Says District of Columbia to Go Ahead With Pot Legalization

Reuters - News Video Online (Feb. 25, 2015) Washington&apos;s mayor says the District of Columbia will move forward with marijuana legalization, despite pushback from Congress. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Marijuana Nowhere Near As Deadly As Alcohol: Study

Marijuana Nowhere Near As Deadly As Alcohol: Study

Newsy (Feb. 25, 2015) A new study says marijuana is about 114 times less deadly than alcohol. Video provided by Newsy
Powered by NewsLook.com
Researchers Replace Damaged Hands With Prostheses

Researchers Replace Damaged Hands With Prostheses

Newsy (Feb. 25, 2015) Scientists in Austria have been able to fit patients who&apos;ve lost the use of a hand with bionic prostheses the patients control with their minds. 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