Featured Research

from universities, journals, and other organizations

Chain reactions identified within the brain

Date:
October 25, 2010
Source:
Massachusetts Institute of Technology
Summary:
As anyone who as ever picked up a guitar or a tennis racket knows, precise timing is often an essential part of performing complex tasks. Now, by studying the brain circuits that control bird song, researchers have identified a "chain reaction" of brain activity that appears to control the timing of song.

Neurons work like a chain of dominos to control action sequences.
Credit: iStockphoto/Hans Slegers

As anyone who as ever picked up a guitar or a tennis racket knows, precise timing is often an essential part of performing complex tasks. Now, by studying the brain circuits that control bird song, MIT researchers have identified a "chain reaction" of brain activity that appears to control the timing of song.

Related Articles


The song of the zebra finch is very stereotypic; each song lasts about 1 second, and consists of multiple syllables whose timing is almost precisely the same from one performance to the next. "It's a great model system for studying how the brain controls actions," says Michale Fee, senior author of the study and a member of the McGovern Institute for Brain Research.

The brain structures involved in bird song production have been identified, and Fee and colleagues had previously shown that the tempo of the song is controlled by a brain area known as HVC. During the 1-second song, individual neurons in HVC fire just one short burst of activity at a precise time point within the song. Different neurons fire at different times, so the activity of these neurons represents a 'time stamp' that causes the correct instructions to be sent to the vocal organs at each instant within the song.

But how does each HVC neuron know when to fire with such perfect timing? Several different ideas have been proposed, but one especially appealing idea is the "synfire chain" model, in which neurons fire in a chain reaction -- each one triggering the next in the sequence, like a cascade of falling dominos.

In a new study, which appears in the October 24 online issue of Nature, Fee and colleagues have now tested this idea using intracellular recordings, an approach that can record tiny voltage fluctuations in individual HVC neurons. In a technical tour-de-force, they developed a method in which these recordings could be made while the bird was freely moving around his cage and engage in natural behaviors such as singing.

Their results support the chain of dominoes model. When individual HVC neurons fire, they do so suddenly, as if hit by the preceding domino. There was no prior build-up of activity; instead, each neuron remained silent until its turn came to fire, at which point it showed a sudden burst of activity, presumably caused by excitatory input from the previous neuron in the chain. In further experiments, the authors showed that this burst of activity is triggered suddenly by an all-or-none influx of calcium through specialized membrane channels that open in response to this excitatory input.

The MIT researchers also showed that the timing of neural bursts in HVC neurons is not easily disturbed by small electrical perturbations. That's important, explains first author Michael Long, who is now at New York University's Langone Medical Center. "If one neuron made a mistake in its timing, every subsequent neuron down the chain would also be off. It would be like a musician with no sense of rhythm."

"This is the first time we've been able to understand the generation of a learned behavioral sequence," says Fee. "We predict that similar mechanisms probably exist in other brains, including our own."


Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. Note: Materials may be edited for content and length.


Journal Reference:

  1. Michael A. Long, Dezhe Z. Jin, Michale S. Fee. Support for a synaptic chain model of neuronal sequence generation. Nature, 2010; DOI: 10.1038/nature09514

Cite This Page:

Massachusetts Institute of Technology. "Chain reactions identified within the brain." ScienceDaily. ScienceDaily, 25 October 2010. <www.sciencedaily.com/releases/2010/10/101024144134.htm>.
Massachusetts Institute of Technology. (2010, October 25). Chain reactions identified within the brain. ScienceDaily. Retrieved October 31, 2014 from www.sciencedaily.com/releases/2010/10/101024144134.htm
Massachusetts Institute of Technology. "Chain reactions identified within the brain." ScienceDaily. www.sciencedaily.com/releases/2010/10/101024144134.htm (accessed October 31, 2014).

Share This



More Mind & Brain News

Friday, October 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Studying Effects of Music on Dementia Patients

Studying Effects of Music on Dementia Patients

AP (Oct. 30, 2014) The University of Wisconsin-Milwaukee is studying the popular Music and Memory program to see if music, which helps improve the mood of Alzheimer's patients, can also reduce the use of prescription drugs for those suffering from dementia. (Oct. 30) Video provided by AP
Powered by NewsLook.com
Techy Tots Are Forefront of London's Baby Show

Techy Tots Are Forefront of London's Baby Show

AP (Oct. 28, 2014) Moms and Dads get a more hands-on approach to parenting with tech-centric products for raising their little ones. (Oct. 28) Video provided by AP
Powered by NewsLook.com
Cocoa Could Be As Good For Memory As It Is For A Sweet Tooth

Cocoa Could Be As Good For Memory As It Is For A Sweet Tooth

Newsy (Oct. 27, 2014) Researchers have come up with another reason why dark chocolate is good for your health. A substance in the treat can reportedly help with memory. Video provided by Newsy
Powered by NewsLook.com
Five-Year-Olds Learn Coding as Britain Eyes Digital Future

Five-Year-Olds Learn Coding as Britain Eyes Digital Future

AFP (Oct. 27, 2014) Coding has become compulsory for children as young as five in schools across the UK. Making it the first major world economy to overhaul its IT teaching and put programming at its core. Duration: 02:19 Video provided by AFP
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