Differential effects of acetylcholine on neuronal activity and interactions in the auditory cortex of the guinea-pig.


During normal brain operations, cortical neurons are subjected to continuous cholinergic modulations. In vitro studies have indicated that, in addition to affecting general cellular excitability, acetylcholine also modulates synaptic transmission. Whether these cholinergic mechanisms lead to a modulation of functional connectivity in vivo is not yet known. Herein, the effects were studied of an iontophoretic application of acetylcholine and of the muscarinic agonist, carbachol, on the ongoing activity and co-activity of neurons simultaneously recorded in the auditory cortex of the anaesthetized guinea-pig. Iontophoresis of cholinergic agonists mainly affected the spontaneous firing rates of auditory neurons, affected autocorrelations less (in most cases their central peak areas were reduced), and rarely affected cross-correlations. These findings are consistent with cholinergic agonists primarily affecting the excitability of cortical neurons rather than the strength of cortical connections. However, when changes of cross-correlations occurred, they were usually not correlated with concomitant changes in average firing rates nor with changes in autocorrelations, which suggests a secondary cholinergic effect on specific cortico-cortical or thalamo-cortical connections.

Extracted Key Phrases

10 Figures and Tables


Citations per Year

102 Citations

Semantic Scholar estimates that this publication has 102 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Shulz1997DifferentialEO, title={Differential effects of acetylcholine on neuronal activity and interactions in the auditory cortex of the guinea-pig.}, author={Daniel Shulz and Samia Cohen and Sebastian Haidarliu and Ehud Ahissar}, journal={The European journal of neuroscience}, year={1997}, volume={9 2}, pages={396-409} }