  The generation of spikes by neurons is energetically a costly process. This
paper studies the consumption of energy and the information entropy in the
signalling activity of a model neuron both when it is supposed isolated and
when it is coupled to another neuron by an electrical synapse. The neuron has
been modelled by a four dimensional Hindmarsh-Rose type kinetic model for which
an energy function has been deduced. For the isolated neuron values of energy
consumption and information entropy at different signalling regimes have been
computed. For two neurons coupled by a gap junction we have analyzed the roles
of the membrane and synapse in the contribution of the energy that is required
for their organized signalling. Computational results are provided for cases of
identical and nonidentical neurons coupled by unidirectional and bidirectional
gap junctions. One relevant result is that there are values of the coupling
strength at which the organized signalling of two neurons induced by the gap
junction takes place at relatively low values of energy consumption and the
ratio of mutual information to energy consumption is relatively high.
Therefore, communicating at these coupling values could be energetically the
most efficient option.
