The model is based on the electrochemical equation (3). We will count the membrane potential from its level 
at rest, i.e. let's put 
, or 
. Let us similarly introduce notations for those measured from 
equilibrium electrochemical potentials 
и 
. It is clear that the differences remain: 
и 
. In creating membrane potential other than ions 
и 
other ions also take part, in particular, ions 
. Let us denote their total electrochemical potential by 
, respectively 
. To balance the membrane currents, the term should be added to equation (3): 
. This current is called leakage current. For the giant squid axon, A. Hodgkin and A. Huxley experimentally found the following values: 
mv, 
MW, 
mw