Linked Life Data

10985690

Source:http://linkedlifedata.com/resource/pubmed/id/10985690

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2001-1-9
pubmed:abstractText
Primary sensory and motor areas of the cerebral cortex contain organised maps of the body. These maps appear to reorganise after damage to the peripheral parts of the sensory or motor systems, so that the cortical representation of undamaged structures expands at the expense of the damaged parts. Several studies in animals have suggested that decreased activity of the inhibitory GABAergic neurones is responsible for driving these changes. However, whether similar mechanisms sustain the effects in the longer term in humans is unknown. The present study addressed this question by examining reorganisation of sensorimotor areas of cortex in six unilateral upper limb amputees several years after the initial injury. We measured two independent indices of GABAergic function. Volumes of distribution of GABA(A) receptors were determined from 11C-flumazenil binding measured with positron emission tomography (PET). The strength of inhibition in the motor cortex was measured with paired-pulse transcranial magnetic stimulation. In the six amputees taken as a whole and compared with 24 normal subjects, there was a highly significant increase in 11C-flumazenil binding in the upper limb region of primary sensorimotor cortex bilaterally and in medial frontal cortex of the hemisphere contralateral to the amputation. Surprisingly, however, there was no change in the time course or strength of intra-cortical inhibition in the motor cortex of the amputees compared with matched control subjects. The increased 11C-flumazenil binding may reflect up-regulation of GABA(A) receptors to compensate for a decrease in the GABA content or activity of inhibitory neurones. Up-regulation of GABA(A) receptors may also indicate that long-term changes require stabilisation of cortical organisation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0014-4819
pubmed:author
pubmed:issnType
Print
pubmed:volume
133
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
552-6
pubmed:dateRevised
2009-11-11
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Long-term changes of GABAergic function in the sensorimotor cortex of amputees. A combined magnetic stimulation and 11C-flumazenil PET study.
pubmed:affiliation
Department of Anatomy and Physiology, Centre de Recherche, Université Laval-Robert Giffard, Beauport, QC, Canada. charles.capaday@anm.ulaval.ca
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't