Gamma Oscillations Facilitate Effective Learning in Excitatory-Inhibitory Balanced Neural Circuits.

Kwan Tung Li,Junhao Liang,Changsong Zhou,Jianzhong Su

doi:10.1155/2021/6668175

Abstract

Gamma oscillation in neural circuits is believed to associate with effective learning in the brain, while the underlying mechanism is unclear. This paper aims to study how spike-timing-dependent plasticity (STDP), a typical mechanism of learning, with its interaction with gamma oscillation in neural circuits, shapes the network dynamics properties and the network structure formation. We study an excitatory-inhibitory (E-I) integrate-and-fire neuronal network with triplet STDP, heterosynaptic plasticity, and a transmitter-induced plasticity. Our results show that the performance of plasticity is diverse in different synchronization levels. We find that gamma oscillation is beneficial to synaptic potentiation among stimulated neurons by forming a special network structure where the sum of excitatory input synaptic strength is correlated with the sum of inhibitory input synaptic strength. The circuit can maintain E-I balanced input on average, whereas the balance is temporal broken during the learning-induced oscillations. Our study reveals a potential mechanism about the benefits of gamma oscillation on learning in biological neural circuits.

Highlights

The emergence of oscillations in neurophysiological signals within different frequency bands is commonly observed in mammal brain [1,2,3,4]
We study learning in neural networks through spike-timing-dependent plasticity (STDP), a widelyobserved phenomenon in experiments
We showed that the synchronous dynamics forms a special network structure after learning

Summary

Introduction

The emergence of oscillations in neurophysiological signals within different frequency bands is commonly observed in mammal brain [1,2,3,4]. When animals or humans are performing different tasks or at the resting state, neural oscillations within specific frequency bands would be detected in specific brain regions. Learning is believed to accompany with structural changes of neural circuits in the brain and is frequently observed to associate with the emergence of gamma band oscillations [6,7,8]. Structural clusters are formed in neural networks in both the prefrontal cortex and hippocampus, which are behaviorally relevant for the recall of short-term memory and the later consolidation of long-term memory [9, 10]

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