Navigation Links
Observation about how nervous system learns and encodes motion could improve stroke recovery
Date:1/7/2010

CAMBRIDGE, Mass., January 7, 2010 Bioengineers have taken a small step toward improving physical recovery in stroke patients by showing that a key feature of how limb motion is encoded in the nervous system plays a crucial role in how new motor skills are learned.

Published in the November 25, 2009 issue of Neuron, a Harvard-based study about the neural learning elements responsible for motor learning may help scientists design rehabilitation protocols in which motor adaptation occurs more readily, potentially allowing for a more rapid recovery.

Neuroscientists have long understood that the brain's primary motor cortex and the body's low-level peripheral stretch sensors encode information about the position and velocity of limb motion in a positively-correlated manner rather than as independent variables.

"While this correlation between the brain's encoding of the position and the velocity of motion is well-known, its potential importance and practical use has been unclear until now," says coauthor Maurice A. Smith, Assistant Professor of Bioengineering at the Harvard School of Engineering and Applied Sciences (SEAS) and the Center for Brain Science in the Faculty of Arts and Sciences.

Smith and colleagues showed that the correlated neural tuning to position and velocity is also present in the neural learning elements responsible for motor learning. Moreover, this correlated drive can explain key features of the motor adaptation process.

To study and record motor adaptation, the researchers had subjects grasp a robotic arm. The device was programmed to simulate novel physical dynamics as subjects made reaching motions. In addition, the team used a newly developed measurement technique called an "error-clamp" to tease apart the resulting data.

The method measures motor output during learning, allowing learning-related changes in motor output over the course of a movement to be dissociated from feedback adjustments that correct motor errors that happen simultaneously.

"Conceptually, this error-clamp is analogous to a voltage-clamp, commonly used in electrophysiology to measure how ions move through a neuron's membrane when it fires," explains lead author Gary C. Sing, a graduate student at SEAS. "The general idea is that devising an experimental method to clamp and control the key variable in an experiment can allow for greater insight into the underlying physiology."

Analysis of the data extracted by the error-clamp technique led to the creation of a computational model that identifies a set of vectors that characterize the principal components of motor adaptation in the state space of physical motion. While such analysis is commonplace in systems engineeringfor example, in evaluating how a bridge might react to high winds or earthquakesthe method has only been recently applied to how motor output evolves.

"We observed that the initial stages of motor learning are often quick but non-specific, whereas later stages of learning are slower and more precise," says Sing. "Further, we saw that some physical patterns of movement are learned more quickly than others."

By understanding what types of motor adaptations are easier to learn, the researchers hope to design rehabilitation activities that will encourage patients to use an affected limb more.

"In stroke rehabilitation, patients who make a greater effort to use their impaired limbs can achieve better outcomes," says Smith. "However, there is often a vicious cycle, as a patient is far less likely to use an impaired limb if his or her other limb is fine. This pattern slows recovery and leads to greater impairment of the affected limb."

Smith and his colleagues are beginning studies with stroke patients to determine whether training them with such optimized patterns will, in fact, improve their rate of motor learning and speed up recovery.

More broadly, untangling the algorithms the brain uses for motor learning could help improve a wide range of neural and muscular rehabilitation programs. The researchers also anticipate that such findings could be one day be adapted for enhancing the brain/machine interfaces increasingly used for those with amputated limbs.


'/>"/>

Contact: Michael Patrick Rutter
mrutter@seas.harvard.edu
617-496-3815
Harvard University
Source:Eurekalert  

Related biology news :

1. UCSD researchers make first direct observations of biological particles in high-altitude ice clouds
2. ESAs Earth observation missions: Sharing teams and facilities boosts efficiency
3. Indigenous peoples at world summit to share climate change observations, coping techniques
4. GKSS to invest 12 million euros ($15.48 million) in a new observation system for the North Sea
5. Observations from space: NASA environmental data and lung disease
6. In computer models and observations, researchers see potential for significant red tide season
7. Whos bad? Chimps figure it out by observation
8. Stanford researchers make first direct observation of 3-D molecule folding in real time
9. Space technology put into service for global water resources observations
10. Earth Observation essential for geohazard mitigation
11. Special excerpt of Environmental Policy and Law about human rights and the environment
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Observation about how nervous system learns and encodes motion could improve stroke recovery
(Date:6/27/2016)... , June 27, 2016 Research and ... North America 2016-2020" report to their offering. ... North America to grow at a CAGR of ... been prepared based on an in-depth market analysis with inputs from ... prospects over the coming years. The report also includes a discussion ...
(Date:6/22/2016)... , June 22, 2016  The American College of Medical ... Show Executive Magazine as one of the fastest-growing trade ... 25-27 at the Bellagio in Las Vegas ... highest percentage of growth in each of the following categories: ... companies and number of attendees. The 2015 ACMG Annual Meeting ...
(Date:6/22/2016)... 22, 2016   Acuant , the ... solutions, has partnered with RightCrowd ® ... Visitor Management, Self-Service Kiosks and Continuous Workforce ... add functional enhancements to existing physical access ... venues with an automated ID verification and ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... 2016  Alex,s Lemonade Stand Foundation (ALSF), a leading ... open a state-of-the-art bioinformatics lab, using ,big data, to ... comes as Liz Scott , co-executive director of ... Summit in Washington, D.C. , hosted ... and advocate of pediatric cancer research and awareness. ...
(Date:6/27/2016)... 2016  Global demand for enzymes is forecast ... to $7.2 billion.  This market includes enzymes used ... biofuel production, animal feed, and other markets) and ... Food and beverages will remain the largest market ... of products containing enzymes in developing regions.  These ...
(Date:6/27/2016)... 27, 2016 /PRNewswire/ - BIOREM Inc. (TSX-V: BRM) ("Biorem" or ... its major shareholders, Clean Technology Fund I, LP and ... based venture capital funds which together hold ... a fully diluted, as converted basis), that they have ... entire equity holdings in Biorem to TUS Holdings Co. ...
(Date:6/27/2016)... June 27, 2016  Sequenom, Inc. (NASDAQ: ... healthier lives through the development of innovative products and ... the United States denied its petition ... claims of Sequenom,s U.S. Patent No. 6,258,540 (",540 Patent") ... established by the Supreme Court,s Mayo Collaborative Services v. ...
Breaking Biology Technology: