Modeling of a memristor-coupled neural circuit with piezoelectric channel

Abstract

Electrical activities in biological neurons result from stochastic diffusion of intracellular ions and bidirectional pumping of extracellular and intracellular ions across the membrane channels, and electromagnetic field energy is changed during energy exchange between magnetic field and electric field in/out of the cell. For circuit approach of perceiving functions of the biological neurons, the branch circuits composed of specific components can be activated to express the biophysical property of ion channels. In this paper, a neural circuit is proposed by using three branch circuits in parallel, one branch circuit is incorporated with a CCM (charge-controlled memristor), and one of the inductive branch circuit is connected with a piezoelectric device, which is capable for perceiving acoustic waves. Without the participation of piezoelectric ceramic, the symmetrical combination of the two inductors and the memristor element seldom triggers chaotic patterns, the physical mechanism lies in continuous excitation and regulation from the piezoelectric source, which enhances energy exchange between different energy terms/branch circuits. The incorporation of piezoelectric device in one of the inductive branch circuit activates equivalent but changeable capacitive property into the neural circuit; as a result, the two inductive ion channels/branch circuits have asymmetrical impacts on ions propagation, which supports different firing patterns in the electrical activities. The thermal power is calculated for estimating the thermal effect on neural activities and the mean power (<T_P>) is used to identify the functional state and energy efficiency of neurons. This method effectively compensates for the deficiency in previous studies that only focused on electrical behavior while ignoring thermal energy consumption. It is confirmed that functional ion channel endowed with piezoelectric perception can wake the neurons to give appropriate electrical response and energy regulation, which supports suitable firing patterns. Further taming the intensity of noisy excitation, similar coherence behaviors are induced in the electrical activities. It provides clues to design neural circuits when capacitors are not available or suffering breakdown because of electric shock.