Skip Navigation



Cerebral Cortex Advance Access published online on January 28, 2009
Cerebral Cortex, doi:10.1093/cercor/bhn258
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
19/10/2411    most recent
bhn258v1
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 Lucas-Meunier, E.
Right arrow Articles by Fossier, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lucas-Meunier, E.
Right arrow Articles by Fossier, P.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2009. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org

Involvement of Nicotinic and Muscarinic Receptors in the Endogenous Cholinergic Modulation of the Balance between Excitation and Inhibition in the Young Rat Visual Cortex

Estelle Lucas-Meunier1, Cyril Monier2, Muriel Amar1, Gérard Baux1, Yves Frégnac2 and Philippe Fossier1

1 Laboratoire de neurobiologie cellulaire et moléculaire, UPR CNRS 9040, 91198 Cedex, Gif-sur-Yvette, France, 2 Unité de neurosciences intégratives et computationnelles, UPR CNRS 2191, 91198 Cedex, Gif-sur-Yvette, France

Address correspondence to email: mamar{at}nbcm.cnrs-gif.fr.

This study aims to clarify how endogenous release of cortical acetylcholine (ACh) modulates the balance between excitation and inhibition evoked in visual cortex. We show that electrical stimulation in layer 1 produced a significant release of ACh measured intracortically by chemoluminescence and evoked a composite synaptic response recorded intracellularly in layer 5 pyramidal neurons of rat visual cortex. The pharmacological specificity of the ACh neuromodulation was determined from the continuous whole-cell voltage clamp measurement of stimulation-locked changes of the input conductance during the application of cholinergic agonists and antagonists. Blockade of glutamatergic and {gamma}-aminobutyric acid (GABAergic) receptors suppressed the evoked response, indicating that stimulation-induced release of ACh does not directly activate a cholinergic synaptic conductance in recorded neurons. Comparison of cytisine and mecamylamine effects on nicotinic receptors showed that excitation is enhanced by endogenous evoked release of ACh through the presynaptic activation of {alpha}*β4 receptors located on glutamatergic fibers. DHβE, the selective {alpha}4β2 nicotinic receptor antagonist, induced a depression of inhibition. Endogenous ACh could also enhance inhibition by acting directly on GABAergic interneurons, presynaptic to the recorded cell. We conclude that endogenous-released ACh amplifies the dominance of the inhibitory drive and thus decreases the excitability and sensory responsiveness of layer 5 pyramidal neurons.

Key Words: acetylcholine • cortical network • patch-clamp • pyramidal neuron • rat visual cortex • synaptic integration

Estelle Lucas-Meunier and Cyril Monier have contributed equally to this work.


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.