Effects of extracellular electric fields on electrical activities of two-compartment autaptic-neurons

Abstract

Abstract In our work, we follow a modeling approach to investigate how extracellular electric fields affect the dynamics of two-compartment autaptic-neurons with morphological structures and how those effects translate into changes in electrical activities. Inter-spikes intervals bifurcation diagrams, frequency–input curves as well as phase-locking ratios are used to describe neural firing patterns, input sensitivities as well as mode-locking states. Modulated by extracellular electric fields, the autaptic-neurons exhibit subthreshold oscillation, tonic spiking, bursting and chaotic firing patterns. The input sensitivities and the mode-locking states are enhanced or suppressed depending on the parameters of extracellular electrical fields. Compared with autaptic-neurons with symmetrical structures, the autaptic-neuron with nonsymmetrical morphology have higher input sensitivities to extracellular electric fields, which suggest that neural geometric features play a crucial role in electric field effects on behaviors of neuron. Those results in our works provide a systematic understanding of effects of extracellular electric fields on the electrical activities of autaptic-neurons, which are further steps towards improving the design of electromagnetic brain stimulations.