Numerical simulation of electrochemical interaction between cholinergic and adrenergic neurones

A mathematical model of cholinergic and adrenergic neurones has been developed, based on the electrophysiological data of the dynamics of nerve-pulse propagation along the geometrically non-uniform unmyelinated nerve axon and the pharmacokinetic mechanisms of electrochemical coupling in the cholinergic/adrenergic synapses. The model assumes that adrenoceptors, located at the axo-axonic presynaptic junction, provide a presynaptic inhibition of an excitatory signal transfer via the cholinergic neurone. The model quantitatively describes: (a) the processes of nerve-pulse propagation along the axons, (b) the neurotransmitters´ release, (c) diffusion of their fractions into the synaptic cleft, (d) binding with receptors located on the postsynaptic membranes, and (e) the development of fast excitatory/inhibitory postsynaptic potentials (EPSP/IPSP). Time relationships between the EPSP and IPSP development in the axo-axonal junction are established. The model predicts the dose-dependent influence of adrenergic agonists and antagonists on the dynamics of neural circuit function