Featured Research

from universities, journals, and other organizations

These boosts are made for walkin': Visual system amplifier directly activated by locomotion

Date:
March 13, 2014
Source:
University of California, San Francisco (UCSF)
Summary:
The body may get help in fast-changing situations from a specialized brain circuit that causes visual system neurons to fire more strongly during locomotion, neuroscientists have discovered. It has long been known that nerve cells in the visual system fire more strongly when we pay close attention to objects than when we view scenes more passively. But the new research breaks new ground, mapping out a visual system amplifier that is directly activated by walking or running.

It has long been known that nerve cells in the visual system fire more strongly when we pay close attention to objects than when we view scenes more passively. But the new research breaks new ground, mapping out a visual system amplifier that is directly activated by walking or running.
Credit: © mezzotint_fotolia / Fotolia

Whether you're a Major League outfielder chasing down a hard-hit ball or a lesser mortal navigating a busy city sidewalk, it pays to keep a close watch on your surroundings when walking or running. Now, new research by UC San Francisco neuroscientists suggests that the body may get help in these fast-changing situations from a specialized brain circuit that causes visual system neurons to fire more strongly during locomotion.

Related Articles


There has been a great deal of research on changes among different brain states during sleep, but the new findings, reported in the March 13 issue of Cell, provide a compelling example of a change in state in the awake brain.

It has long been known that nerve cells in the visual system fire more strongly when we pay close attention to objects than when we view scenes more passively. But the new research, led by Yu Fu, PhD, a postdoctoral fellow in the UCSF lab of senior author Michael P. Stryker, PhD, the W.F. Ganong Professor of Physiology, breaks new ground, mapping out a visual system amplifier that is directly activated by walking or running.

Though this circuit has not yet been shown to exist in humans, Stryker is designing experiments to find out if it does. He said he would be surprised if his group did not identify a similar mechanism in people, since such systems have been found in fruit flies, and the mouse visual system has so far proved to be a good model of many aspects of human vision.

"The sense of touch only tells you about objects that are close, and the auditory system is generally not as sensitive as the visual system to the exact position of objects," he said. "It seems that it would be generally useful to have vision -- the sensory modality that tells you the most about things that are far away -- work better as you're moving through the world."

Stryker said that the neural system identified in the new work may have evolved to conserve energy, by allowing the brain to operate at less than peak efficiency in less demanding behavioral situations. "When you don't need your visual system to be in a high-gain state, your brain may use a lot less energy in responding," said Stryker. "A change in gain when you're moving is ideally what you'd like to see -- the neuron is doing the same thing that it's always doing, but it's talking louder to the rest of the brain."

In the new research, mice were allowed to walk or run freely on a Styrofoam ball suspended on an air cushion while the scientists used a technique known as two-photon imaging to monitor the activation of cells in the primary visual area of the brain, known as V1.

The researchers found that a subset of V1 neurons, those that contain a substance called vasoactive intestinal peptide (VIP), were robustly activated in a time-locked fashion purely by locomotion, even in darkness, while other V1 neurons remained largely silent.

The mice were presented with visual stimuli both while motionless and while moving, and measurements showed that walking could increase the response of V1 neurons by more than 30 percent. Moreover, V1 responses to these stimuli increased or declined in tandem with the activity of VIP neurons, and with the starting or stopping of walking by the mice.

To firmly establish that VIP neurons were responsible for these changes, the researchers used optogenetic techniques, inserting light-sensitive proteins exclusively into VIP neurons. Using light to stimulate just this population of cells, the team found that they could emulate the effects of locomotion -- when VIP cells were activated, V1 cells responded more strongly to stimuli, regardless of whether the animals were moving. Conversely, when the researchers specifically targeted and disabled VIP cells, locomotion-induced increases in the response of other V1 cells were abolished.


Story Source:

The above story is based on materials provided by University of California, San Francisco (UCSF). Note: Materials may be edited for content and length.


Journal Reference:

  1. Yu Fu, Jason M. Tucciarone, J. Sebastian Espinosa, Nengyin Sheng, Daniel P. Darcy, Roger A. Nicoll, Z. Josh Huang, Michael P. Stryker. A Cortical Circuit for Gain Control by Behavioral State. Cell, March 2014 DOI: 10.1016/j.cell.2014.01.050

Cite This Page:

University of California, San Francisco (UCSF). "These boosts are made for walkin': Visual system amplifier directly activated by locomotion." ScienceDaily. ScienceDaily, 13 March 2014. <www.sciencedaily.com/releases/2014/03/140313153933.htm>.
University of California, San Francisco (UCSF). (2014, March 13). These boosts are made for walkin': Visual system amplifier directly activated by locomotion. ScienceDaily. Retrieved April 2, 2015 from www.sciencedaily.com/releases/2014/03/140313153933.htm
University of California, San Francisco (UCSF). "These boosts are made for walkin': Visual system amplifier directly activated by locomotion." ScienceDaily. www.sciencedaily.com/releases/2014/03/140313153933.htm (accessed April 2, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Thursday, April 2, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Wound-Healing Laser Soon to Be a Reality Israeli Scientist

Wound-Healing Laser Soon to Be a Reality Israeli Scientist

Reuters - Innovations Video Online (Apr. 1, 2015) — Israeli scientists says laser bonding of tissue allows much faster healing and less scarring. Amy Pollock has more. Video provided by Reuters
Powered by NewsLook.com
Liberia Sees Resurgence of Drug Trafficking as Ebola Wanes

Liberia Sees Resurgence of Drug Trafficking as Ebola Wanes

AFP (Apr. 1, 2015) — The governments of Liberia and Sierra Leone have been busy fighting the menace created by the deadly Ebola virus, but illicit drug lords have taken advantage of the situation to advance the drug trade. Duration: 01:12 Video provided by AFP
Powered by NewsLook.com
Stigma Stalks India's Leprosy Sufferers as Disease Returns

Stigma Stalks India's Leprosy Sufferers as Disease Returns

AFP (Apr. 1, 2015) — The Indian government declared victory over leprosy in 2005, but the disease is making a comeback in some parts of the country, with more than a hundred thousand lepers still living in colonies, shunned from society. Duration: 02:41 Video provided by AFP
Powered by NewsLook.com
7-Year-Old Girl Gets 3-D Printed 'robohand'

7-Year-Old Girl Gets 3-D Printed 'robohand'

AP (Mar. 31, 2015) — Although she never had much interest in prosthetic limbs before, Faith Lennox couldn&apos;t wait to slip on her new robohand. The 7-year-old, who lost part of her left arm when she was a baby, grabbed it as soon as it came off a 3-D printer. (March 31) 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