A novel digital implementation of neuron–astrocyte interactions

Abstract

Recent neurophysiologic findings have shown that astrocytes dynamically regulate the synaptic transmission and they are active partners in neural information processing. Motivated by these findings, a digital circuit to study neuron---astrocyte signaling is presented. The firing dynamics of the neuron is described by Izhikevich model and the $$\hbox {Ca}^{2+}$$Ca2+ dynamics of a single astrocyte explained by a functional model introduced by Postnov and colleagues. Next, a new architecture based on piecewise-linear approximation is proposed for digital implementation of the neuron---astrocyte communication. Considering the results of MATLAB, ModelSim simulations and FPGA implementation, it is demonstrated that the digital astrocyte is able to activate the digital neuron or change the neuron spiking frequency. In this way, astrocytic interaction is able to modulate spike transmission frequency and therefore enhances the information processing capabilities of the neuron circuit. These results could be used in neuromorphic applications which implement biologically brain circuits.