  The recent theoretical and experimental studies have revealed many details of
signal propagation in nervous systems. In this paper an attempt is made to
unify various mathematical models which describe the signal propagation in
nerve fibres. The analysis of existing single models permits to select the
leading physiological effects. As a result, a more general mathematical model
is described based on the coupling of action potentials with mechanical waves
in a nerve fibre. The crucial issue is how to model coupling effects which are
strongly linked to the ion currents through biomembranes.
