Skip Navigation



Cerebral Cortex Advance Access published online on November 7, 2008
Cerebral Cortex, doi:10.1093/cercor/bhn199
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
19/7/1616    most recent
bhn199v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Degos, B.
Right arrow Articles by Maurice, N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Degos, B.
Right arrow Articles by Maurice, N.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2008. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org

Chronic but not Acute Dopaminergic Transmission Interruption Promotes a Progressive Increase in Cortical Beta Frequency Synchronization: Relationships to Vigilance State and Akinesia

Bertrand Degos1, Jean-Michel Deniau1, Mario Chavez2 and Nicolas Maurice1

1 Institut National de la Santé et de la Recherche Médicale U.667, Dynamique et Physiopathologie des Réseaux Neuronaux, Collège de France, 11 place Marcelin Berthelot, 75 231 Paris Cedex 05, France; Université Pierre et Marie Curie, 4 place Jussieu, 75005 Paris, France, 2 Centre National de la Recherche Scientifique, Unité Propre de Recherche 640 – Laboratoire de Neurosciences Cognitives et Imagerie Cérébrale, Hôpital de la Pitié-Salpêtrière, 75 651 Paris Cedex 13, France

Address correspondence to Nicolas Maurice, INSERM U.667, Collège de France, 11 place Marcelin Berthelot, 75 231 Paris Cedex 05, France. Email: nicolas.maurice{at}college-de-france.fr.

Dopaminergic (DA) denervation results in the appearance of an excessive cortical beta frequency synchronization in parkinsonian patients and animal models of the disease. The present study analyzed electrocorticogram signals in awake rats to further characterize this excessive synchronization in terms of time course, relation to motor activity and state of vigilance. Using substantia nigra pars compacta lesions and both acute and chronic pharmacological interruptions of DA transmission, the present data demonstrated that the appearance of excessive beta synchronization requires a prolonged interruption in DA transmission and builds up progressively. This synchronization was vigilance-state dependent and observed solely during awake-like activity. Furthermore, these data demonstrated for the first time that the appearance of akinesia preceded the excessive cortical beta synchronization. In addition, this synchronization was stronger in the motor than in the somato-sensory cortex and in unilaterally compared with bilaterally lesioned animals. Finally, excessive beta synchronization was accompanied by an increased coherence between motor and somato-sensory cortical activities. These data suggest that excessive beta synchronization is associated with plastic processes whose time course is delayed with respect to the akinesia. Moreover, the expression of this phenomenon, which likely reflects functional changes in the cortico-basal ganglia circuits, requires a specific brain state.

Key Words: basal ganglia • cerebral cortex • EEG • oscillations • Parkinson's disease


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.