Featured Research

from universities, journals, and other organizations

Parkinson's disease insights: Damage to control circuits in the brain responsible for habits

Date:
October 19, 2010
Source:
University of Sheffield
Summary:
New research into Parkinson's disease suggests that many of the problems suffered by patients -- difficulties in initiating actions, slow labored movements and tremors -- can be understood in terms of damage to control circuits in the brain responsible for habits.

An international collaboration led by academics at the University of Sheffield has shed new light into Parkinson's disease. The research could help with the development of cures or treatments in the future.

The collaboration, which was led by Professor Peter Redgrave from the University's Department of Psychology, suggests that many of the problems suffered by patients with Parkinson's disease -- difficulties in initiating actions, slow laboured movements and tremors -- can be understood in terms of damage to control circuits in the brain responsible for habits.

The analysis, which is published online and will appear in the November issue of Nature Reviews Neuroscience, has involved combining the experience of an international team of clinical experts to explain why, paradoxically, removal of part of the brain can help sufferers of Parkinson's disease regain smooth initiation of movements.

An important processing unit in the brain (the basal ganglia) is part of two behavioural control circuits -- habitual control, which directs our fast, stimulus-driven automatic, largely unconscious movements; and voluntary goal-directed control, which is driven by a conscious appreciation of the action's outcome. This means goal-directed movements are typically slower, require effort, and can only be done one at a time. Different regions of the basal ganglia are involved in goal-directed and habitual control. An important proposal in the Nature Reviews Neuroscience article is that Parkinson's disease is linked to a preferential loss of the neurotransmitter dopamine from the regions involved in habitual control.

Many of the symptoms of Parkinson's disease can therefore be understood in terms of a catastrophic loss of habits, which means patients have to rely on the goal-directed control system for everything they do. This idea can explain why their movements are slow, effortful and easily interrupted. For example, when approaching a narrow door or object, a patient with Parkinson's disease can suddenly freeze and find it difficult to start again. Under serial goal-directed control, (i.e. you can only think about doing one thing at a time), when the patient stops thinking about walking and starts to think about going through the door or avoiding the object, they stop walking.

The proposed analysis offers a further important insight into the symptoms of Parkinson's disease. At the level of the basal ganglia, the goal-directed and habitual control circuits are physically separated, but down-stream, they converge on shared motor systems (that is, we can do the same action either under goal-directed or habitual control). Numerous experiments show that the loss of dopamine from the basal ganglia increases inhibitory output from the habitual control circuits. Therefore, for a patient with Parkinson's disease to express goal-directed behaviour, they have to overcome the distorting inhibitory signals from the malfunctioning habitual control system. This provides a further reason for why patients find it so difficult to initiate and maintain actions and why their behaviour is so effortful and slow.

These ideas also offer a potential resolution of a continuing paradox in Parkinson's disease research -- why destruction of the parts of the basal ganglia responsible for habits can have such a beneficial effect on Parkinson's disease. Professor Redgrave and his team propose that removal of the distorting inhibitory output from habitual control circuits could make it easier for goal-directed behaviour to be expressed.

It is hoped this new interpretation of Parkinson's disease will help in the discovery of new cures and treatment in the future for the 120,000 people in the UK suffering with the disease. Firstly, by directing attention to what makes the habitual basal ganglia particularly vulnerable, and secondly to parts of the brain where goal-directed behaviour is being disrupted by dysfunctional signals from the circuits responsible for habits.

Neuroscientist Professor Peter Redgrave from the University of Sheffield's Department of Psychology, said: "We hope our analysis provides a better understanding of the link between normal and abnormal functioning in the basal ganglia. This is important because the better your understanding of normal function, the better the questions you can ask about its failings, which hopefully, will direct you towards more effective treatments."


Story Source:

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


Journal Reference:

  1. Peter Redgrave, Manuel Rodriguez, Yoland Smith, Maria C. Rodriguez-Oroz, Stephane Lehericy, Hagai Bergman, Yves Agid, Mahlon R. DeLong, Jose A. Obeso. Goal-directed and habitual control in the basal ganglia: implications for Parkinson's disease. Nature Reviews Neuroscience, 2010; DOI: 10.1038/nrn2915

Cite This Page:

University of Sheffield. "Parkinson's disease insights: Damage to control circuits in the brain responsible for habits." ScienceDaily. ScienceDaily, 19 October 2010. <www.sciencedaily.com/releases/2010/10/101019121802.htm>.
University of Sheffield. (2010, October 19). Parkinson's disease insights: Damage to control circuits in the brain responsible for habits. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2010/10/101019121802.htm
University of Sheffield. "Parkinson's disease insights: Damage to control circuits in the brain responsible for habits." ScienceDaily. www.sciencedaily.com/releases/2010/10/101019121802.htm (accessed October 21, 2014).

Share This



More Health & Medicine News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

CDC Revamps Ebola Guidelines After Criticism

CDC Revamps Ebola Guidelines After Criticism

Newsy (Oct. 21, 2014) The Centers for Disease Control and Prevention have issued new protocols for healthcare workers interacting with Ebola patients. Video provided by Newsy
Powered by NewsLook.com
WHO: Ebola Vaccine Trials to Start a in January

WHO: Ebola Vaccine Trials to Start a in January

AP (Oct. 21, 2014) Tens of thousands of doses of experimental Ebola vaccines could be available for "real-world" testing in West Africa as soon as January as long as they are deemed safe in soon to start trials, the World Health Organization said Tuesday. (Oct. 21) Video provided by AP
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. Video provided by Newsy
Powered by NewsLook.com
CDC Issues New Ebola Guidelines for Health Workers

CDC Issues New Ebola Guidelines for Health Workers

Reuters - US Online Video (Oct. 21, 2014) The U.S. Centers for Disease Control and Prevention has set up new guidelines for health workers taking care of patients infected with Ebola. Linda So reports. Video provided by Reuters
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