Mean field model of acetylcholine mediated dynamics in the cerebral cortex |
| |
Authors: | J M Clearwater C J Rennie P A Robinson |
| |
Institution: | (1) School of Physics, University of Sydney, Sydney, NSW, 2006, Australia;(2) The Brain Dynamics Centre, Westmead Millennium Institute, Westmead Hospital and Western Clinical School of the University of Sydney, Westmead, NSW, 2145, Australia;(3) Faculty of Medicine, University of Sydney, Sydney, NSW, 2006, Australia |
| |
Abstract: | A recent continuum model of the large scale electrical activity of the cerebral cortex is generalized to include cholinergic
modulation. In this model, dynamic modulation of synaptic strength acts over the time scales of nicotinic and muscarinic receptor
action. The cortical model is analyzed to determine the effect of acetylcholine (ACh) on its steady states, linear stability,
spectrum, and temporal responses to changes in subcortical input. ACh increases the firing rate in steady states of the system.
Changing ACh concentration does not introduce oscillatory behavior into the system, but increases the overall spectral power.
Model responses to pulses in subcortical input are affected by the tonic level of ACh concentration, with higher levels of
ACh increasing the magnitude firing rate response of excitatory cortical neurons to pulses of subcortical input. Numerical
simulations are used to explore the temporal dynamics of the model in response to changes in ACh concentration. Evidence is
seen of a transition from a state in which intracortical inputs are emphasized to a state where thalamic afferents have enhanced
influence. Perturbations in ACh concentration cause changes in the firing rate of cortical neurons, with rapid responses due
to fast acting facilitatory effects of nicotinic receptors on subcortical afferents, and slower responses due to muscarinic
suppression of intracortical connections. Together, these numerical simulations demonstrate that the actions of ACh could
be a significant factor modulating early components of evoked response potentials. |
| |
Keywords: | |
本文献已被 PubMed SpringerLink 等数据库收录! |
|