Electrostimulation of electrical circuits in the Aloe vera or Arabidopsis thaliana induces electrotonic potentials that propagate along their leaves. The instantaneous increase or decrease in voltage of stimulating potential generates a nonlinear response in plant tissues. Any electrostimulation that is not instantaneous, such as sinusoidal or triangular functions, results in linear responses in the form of small graded potentials. The amplitude and sign of electrotonic potentials depend on the polarity and the amplitude of applied voltage during electrostimulation. Using the synchronous electrostimulation of a leaf from two different points, we studied the interaction between the electrotonic potentials. If electrical responses with positive fronts collided, they annihilated each other; if an electrical signal with positive front collided with an electrical signal having negative front, they amplified each other. The information gained from this study can be used to elucidate the intracellular and intercellular communications in the form of electrical signals within plants.