Regulation of Irregular Neuronal Firing by Autaptic Transmission

TL;DR

This study uses a biophysical model to show how different types of autaptic self-feedback influence neuronal firing irregularity by modulating burst firing, revealing their role in shaping neurodynamics.

Contribution

It demonstrates how excitatory, inhibitory, and electrical autapses differentially regulate burst firing and firing regularity across various neuron types, advancing understanding of autaptic functions.

Findings

Excitatory and electrical autapses increase burst firing.

Inhibitory autapses decrease burst firing.

Autaptic effects are consistent across neuron modes.

Abstract

The importance of self-feedback autaptic transmission in modulating spike-time irregularity is still poorly understood. By using a biophysical model that incorporates autaptic coupling, we here show that self-innervation of neurons participates in the modulation of irregular neuronal firing, primarily by regulating the occurrence frequency of burst firing. In particular, we find that both excitatory and electrical autapses increase the occurrence of burst firing, thus reducing neuronal firing regularity. In contrast, inhibitory autapses suppress burst firing and therefore tend to improve the regularity of neuronal firing. Importantly, we show that these findings are independent of the firing properties of individual neurons, and as such can be observed for neurons operating in different modes. Our results provide an insightful mechanistic understanding of how different types of autapses shape irregular firing at the single-neuron level, and they highlight the functional importance of autaptic self-innervation in taming and modulating neurodynamics.