Transmission of the change in potential difference across a liquid membrane was investigated based on the knowledge of voltammetry for the ion transfer at the interface of two immiscible electrolyte solutions by use of a U-shaped liquid membrane cell. Two aqueous phases (W1 and W1') containing 0.1 M KCl were set on two 1,2-dichloroethane solution phases (M1 and M2) containing about 10(-5) M potassium tetrakis(4-chlorophenyl)borate (le TCPB-) and 10(-3) M tetrabutylammonium tetrakis(4-chlorophenyl)borate (TBA(+) TCPB-), respectively. W1 and W1' were connected via a salt bridge. Then, an aqueous phase (W2) containing 0.1 M KCl and 10-3 M tetrabutylammonium chloride (TBA(+) Cl-) was put in the bottom of the cell, which was in contact with M1 and M2. Under the initial conditions, the potential difference (E) between W1 and W2 (E-w1w2) was identical with Ew1'-w2 between W1' and W2, and then E-w1 vertical bar(m1) between W1 and M1 and Em vertical bar w2 between M1 and W2 were also identical with E-w/lm(2) between W1' and M2 and EM vertical bar W2 between M2 and W2, respectively. In this case, the W1 vertical bar M1 and the W1'jM2 interfaces were depolarized by the distribution of le, and the M1/W2 and the M2 vertical bar W2 interfaces were depolarized by the distribution of TBA(+). After addition of an adequate volume of 10(-3) M TBA(+) Cl- to Wi, Ewi-wz and E(w)1-w2 were shifted simultaneously. Since Em vertical bar w2 and Emziwz remained unchanged on the addition of TBA*, the change of Ew1'vertical bar M2 was induced by the change of Em2 vertical bar M1. This situation can be considered to be a model of the signal transmission. (C) 2012 Elsevier B.V. All rights reserved.