  This paper concerns the proof of the exponential rate of convergence of the
solution of a Fokker-Planck equation, with a drift term not being the gradient
of a potential function and endowed by Robin type boundary conditions. This
kind of problem arises, for example, in the study of interacting neurons
populations. Previous studies have numerically shown that, after a small period
of time, the solution of the evolution problem exponentially converges to the
stable state of the equation.
