  The paper proposes two dynamical systems based on the generalized
Lotka-Volterra model of three excitable elements interacting through excitatory
couplings. It is shown that for some values of the coupling parameters in the
phase space of systems, there are heteroclinic cycles containing three or six
saddle equilibrium states and heteroclinic curves connecting them. Under
certain external stimuli that transfer the system from a stable zero
equilibrium state to a small neighborhood of the heteroclinic cycle, the phase
trajectory will alternately visit the neighborhood of saddle equilibrium states
(possibly more than once), after which it will return to its initial state. The
described behavior is proposed to be used to simulate switching activity in
neural ensembles. Different transients are determined by different external
stimuli. The passage of the phase point of the system near the saddle
equilibrium states included in the heteroclinic circuit is proposed to be
interpreted as activation of the corresponding element.
