Featured Research

from universities, journals, and other organizations

Gene Essential For Development Of Normal Brain Connections Resulting From Sensory Input Discovered

Date:
January 9, 2004
Source:
University Of California - San Diego
Summary:
Biologists at the University of California, San Diego and the Johns Hopkins University have discovered a gene that plays a key role in initiating changes in the brain in response to sensory experience, a finding that may provide insight into certain types of learning disorders.

Images of neurons from normal mice (left) and from mice lacking CREST gene (right) Credit: Anirvan Ghosh

Biologists at the University of California, San Diego and the Johns Hopkins University have discovered a gene that plays a key role in initiating changes in the brain in response to sensory experience, a finding that may provide insight into certain types of learning disorders.

After birth, learning and experience change the architecture of the brain dramatically. The structure of individual neurons, or nerve cells, changes during learning to accommodate new connections between neurons. Neuroscientists believe these structural changes are initiated when neurons are activated, causing calcium ions to flow into cells and alter the activity of genes.

In a paper featured on the cover of the January 9th issue of the journal Science, biologists at UCSD and the Johns Hopkins University medical school report the discovery of the first gene, CREST, known to mediate these changes in the structure of neurons in response to calcium.

"We discovered the gene CREST using a new method we developed to identify genes that are switched on in the presence of calcium," says Anirvan Ghosh, a professor of biology at UCSD who headed the study. "The brains of mice lacking CREST appear normal at birth, but do not develop normally in response to sensory experience after birth. This parallels some learning disorders in humans where the child appears normal initially, but by the age of two or three years it becomes clear that there are failures in the acquisition of new knowledge."

Neurons from normal mice develop a highly branched tree-like structure. In fact, much of the growth of the brain that occurs soon after birth is the development and branching of dendrites-the part of a nerve cell that receives input from other neurons. Thus, this branching allows neurons to form many different synapses, or connections, with many other neurons, permitting much cross talk between them. Neurons taken from mice lacking the CREST gene are more linear, like a plant shoot.

In addition, when individual neurons kept alive in a Petri dish are stimulated with calcium ions, they respond by developing highly branched dendrites, but neurons taken from mice lacking CREST fail to branch in response to calcium.

"CREST is the first example of a transcription factor-a protein that turns genes on and off-that appears to be specifically required for the development of brain neurons after birth," explains Ghosh, who conducted the study at his former laboratory at Johns Hopkins

His new laboratory at UCSD is currently working to determine what gene is targeted by CREST. Ghosh suspects the CREST gene might be turning on the production of chemicals called growth factors, for the stimulatory effect they have on cell development.

The CREST protein produced by that gene is made in several regions of the brain immediately after birth. In adults, the protein is produced in a region of the brain known as the hippocampus, which plays an important role in learning and memory. Because of this, Ghosh suspects that CREST may be necessary for the storage of new memories and the ability to learn. His laboratory is currently developing mice in which CREST expression is normal throughout most of development, so the brain develops normally, but then shuts off in the hippocampus when the mice reach adulthood. In this way, the researchers can test the specific role of CREST in learning and memory in adults.

"Humans also have CREST, and the CREST gene sequence is highly similar between mice and humans," says Ghosh. "If it turns out that CREST plays a role in learning and memory in the mouse, then it is very likely it also plays a similar role in humans."

The other researchers involved in the study are Hiroyuki Aizawa, Shu-Ching Hu, Kathryn Bobb, Karthik Balakriashnan, Inga Gurevich and Mitra Cowan. The study was supported by the National Institutes of Health, the March of Dimes Birth Defects Foundation, the Klingenstein Foundation, Merck and the Uehara Memorial Foundation.


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. "Gene Essential For Development Of Normal Brain Connections Resulting From Sensory Input Discovered." ScienceDaily. ScienceDaily, 9 January 2004. <www.sciencedaily.com/releases/2004/01/040109065327.htm>.
University Of California - San Diego. (2004, January 9). Gene Essential For Development Of Normal Brain Connections Resulting From Sensory Input Discovered. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2004/01/040109065327.htm
University Of California - San Diego. "Gene Essential For Development Of Normal Brain Connections Resulting From Sensory Input Discovered." ScienceDaily. www.sciencedaily.com/releases/2004/01/040109065327.htm (accessed April 16, 2014).

Share This



More Health & Medicine News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Formerly Conjoined Twins Released From Dallas Hospital

Formerly Conjoined Twins Released From Dallas Hospital

Newsy (Apr. 16, 2014) Conjoined twins Emmett and Owen Ezell were separated by doctors in August. Now, nearly nine months later, they're being released from the hospital. Video provided by Newsy
Powered by NewsLook.com
Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
Cognitive Function: Is It All Downhill From Age 24?

Cognitive Function: Is It All Downhill From Age 24?

Newsy (Apr. 15, 2014) A new study out of Canada says cognitive motor performance begins deteriorating around age 24. 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:
from the past week

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