Navigation Links
Scientists discover how brain's auditory center transmits information for decisions, actions
Date:5/1/2013

Cold Spring Harbor, NY When a pedestrian hears the screech of a car's brakes, she has to decide whether, and if so, how, to move in response. Is the action taking place blocks away, or 20 feet to the left?

One of the truly primal mechanisms that we depend on every day of our lives -- acting on the basis of information gathered by our sense of hearing -- is yielding its secrets to modern neuroscience. A team of researchers from Cold Spring Harbor Laboratory (CSHL) today publishes experimental results in the journal Nature which they describe as surprising. The results fill in a key piece of the puzzle about how mammals act on the basis of sound cues.

It's well known that sounds detected by the ears wind up in a part of the brain called the auditory cortex, where they are translated transduced into information that scientists call representations. These representations, in turn, form the informational basis upon which other parts of the brain can make decisions and issue commands for specific actions.

What scientists have not understood is what happens between the auditory cortex and portions of the brain that ultimately issue commands, say, for muscles to move in response to the sound of that car's screeching brakes. To find out, CSHL Professor Anthony Zador and Dr. Petr Znamenskiy trained rats to listen to sounds and to make decisions based on those sounds. When a high-frequency sound is played, the animals are rewarded if they move to the left. When the sound is low-pitched, the reward is given if the animal moves right.

To the striatum

On the simplest level, says Zador, "we know that sound is coming into the ear; and we know what's coming out in the end a decision," in the form of a muscle movement. The surprise, he says, is the destination of the information used by the animal to perform this task of discriminating between sounds of high and low frequency, as revealed in his team's experiments.

"It turns out the information passes through a particular subset of neurons in the auditory cortex whose axons wind up in another part of the brain, called the striatum," says Zador. The classic series of experiments that provided inspiration and a model for this work, performed at Stanford University by William Newsome and colleagues, involved the visual system of primates, and had led Zador to expect by analogy that representations formed in the auditory cortex would lead to other locations within the cortex.

These experiments in rats have implications for how neural circuits make decisions, according to Zador. Even though many neurons in auditory cortex are "tuned" to low or high frequencies, most do not transmit their information directly to the striatum. Rather, their information is transmitted by a much smaller number of neurons in their vicinity, which convey their "votes" directly to the striatum.

"This is like the difference between a direct democracy and a representative democracy, of the type we have in the United States," Zador explains. "In a direct democracy model of how the auditory cortex conveys information to the rest of the brain, every neuron activated by a low- or high-pitched sound would have a 'vote.' Since there is noise in every perception, some minority of neurons will indicate 'low' when the sound is in fact 'high,' and vice-versa. In the direct democracy model, the information sent to the striatum for further action would be the equivalent of a simple sum of all these votes.

"In contrast and this is what we found to be the case the neurons registering 'high' and 'low' are represented by a specialized subset of neurons in their local area, which we might liken to members of Congress or the Electoral College: these in turn transmit the votes of the larger population to the place -- in this case the auditory striatum -- in which decisions are made and actions are taken."

"Corticostriatal neurones in auditory cortex drive decisions during auditory discrimination" appears online ahead of print in Nature on May 1, 2013. the authors are: Petr Znamenskiy and Anthony M. Zador. the paper can be obtained online at http://www.nature.com


'/>"/>

Contact: Peter Tarr
tarr@cshl.edu
516-367-8455
Cold Spring Harbor Laboratory
Source:Eurekalert

Related biology news :

1. Stanford scientists develop gene therapy approach to grow blood vessels in ischemic limbs
2. Queens scientists seek vaccine for Pseudomonas infection
3. Scientists produce eye structures from human blood-derived stem cells
4. American Society of Plant Biologists honors early career women scientists
5. Brandeis scientists win prestigious prize for circadian rhythms research
6. Scientists discover new method of proton transfer
7. Salk scientists open new window into how cancers override cellular growth controls
8. WileyChina.com - Now Featuring Bespoke Pages for China’s Life Scientists
9. Scientists win $2 million to study new pathway in development and maintenance of lymphoma
10. UGA scientists reveal genetic mutation depicted in van Goghs sunflower paintings
11. Genetic mutation depicted in van Goghs sunflower paintings revealed by scientists
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/2/2017)... Feb. 1, 2017  Central to its deep ... advances worldwide, The Japan Prize Foundation today announced ... have pushed the envelope in their respective fields ... Three scientists are being recognized with the 2017 ... not only contribute to the advancement of science ...
(Date:1/26/2017)... -- Crossmatch, a leading provider of security and identity management ... fraud, waste and abuse in assistance operations around the ... Disaster Relief conference in Panama City ... foreign assistance organizations throughout Latin America ... largely unacknowledged problem in the foreign assistance and disaster ...
(Date:1/24/2017)... Jan. 24, 2017  It sounds simple and ... that monitors vital signs and alerts parents on ... oxygen saturation level drops. But pediatric experts argue ... parents, with no evidence of medical benefits, especially ... marketed aggressively to parents of healthy babies, promising ...
Breaking Biology News(10 mins):
(Date:2/23/2017)... , Feb. 23, 2017 /PRNewswire/ - The Fight ... for Cancer Research (OICR) are pleased to report that ... A financing, with Johnson & Johnson Innovation – JJDC, ... include venture groups HealthCap, TPG Biotechnology Partners, and Genesys ... ...
(Date:2/23/2017)... -- Seattle,s upscale Capitol Hill neighborhood, with its swanky shops, parks and ... lice treatment salon to set up shop. But there,s ... French bistro on E Madison Ave, and CEO Maria ... lice clinic, we pride ourselves on being a destination for ... the stigma associated with lice. Everyone can get lice – ...
(Date:2/23/2017)... ... February 23, 2017 , ... ... in a published evaluation of multiple immunoassay-based threat detection technologies by researchers ... Laboratory, PathSensors’ CANARY® biosensor threat detection technology was found to have the ...
(Date:2/23/2017)... NC (PRWEB) , ... February 23, 2017 , ... ... to announce a new partnership with Compass Research . GGI's mission is to ... a vaccine to a child in need in honor of each clinical trial volunteer. ...
Breaking Biology Technology: