Astrocyte mediated firing activities and synchronization in a heterogeneous neuronal network

Astrocytes have been demonstrated to actively participate in modulating neural electrical activity and coordinating synchronization transitions between homogeneous neurons. However, their role in heterogeneous neuronal networks is not yet clear. To bridge this research gap, according to the operational mechanism of tripartite synapses, a tripartite synapse model comprising an HR neuron, a FHN neuron, and an astrocyte is developed in this study. To elucidate the electrical activity of the astrocyte-dressed heterogeneous neuronal network, several numerical analyses are conducted. The findings indicate that an enhancement in synaptic coupling strength and astrocytic feedback not only resulted in transitions in firing patterns but also facilitated synchronous firing within heterogeneous neuronal networks. In particular, the intracellular Ca2+ oscillation is analyzed, revealing that when the heterogeneous neuronal network exhibits periodic spiking, the amplitudes of Ca2+ oscillation remain constant and are independent of firing frequency. Conversely, in the case of bursting firing, a greater number of spikes within each burst, the higher the peak amplitude of intracellular Ca2+ oscillation. Finally, an astrocyte-neuron coupling circuit is designed using current-mode devices to enhance accuracy and reduce power consumption. The PSpice simulation results validate the theoretical analysis and demonstrate its physical feasibility.