[Oscillations in the transepithelial electric potential and current under the influence of lithium]

One can induce sustained oscillations of the spontaneous potential of the frog epithelium by replacing whole or part of the sodium of the external medium with lithium; in the same conditions, the electric current at imposed potential gives damped oscillations. The shape of the oscillations varies much according to the external medium. In the case of the quasi-sinusoidal oscillations, The period is always about 10 mn. We suggest formulating this phenomenon within the framework of the dissipative structurations in non-equilibrium thermodynamics.