Regime Mapping of Oscillatory States in Balanced Spiking Networks with Multiple Time Scales

TL;DR

This study systematically maps how synaptic decay, conduction delay, and plasticity rate influence oscillatory states in balanced spiking networks, providing visual regime maps and insights into rhythm mechanisms.

Contribution

It introduces a comprehensive regime mapping approach combining simulations and spectral analysis to characterize oscillatory transitions in balanced spiking networks.

Findings

Increasing plasticity rate expands oscillatory regions to shorter decay times.

Delay jitter enhances rhythmic coherence without changing mean firing rate.

STDP freezing weakens rhythmic coherence in the network.

Abstract

Balanced spiking networks can transition between silent, asynchronous-irregular, and oscillatory states depending on interacting synaptic and temporal time scales, while their joint parameter structure remains incompletely characterized. In this work, we systematically map how postsynaptic decay ({\tau}s), conduction delay (d), and plasticity rate ({\lambda}p) jointly shape oscillatory regimes in recurrent leaky integrate-and-fire networks. By combining Brian2 simulations across the ({\tau}s, d, {\lambda}p) space with a coarse Hopf-reference boundary, we construct regime maps that directly visualize SIL-AI-OSC transitions and corresponding spectral prominence landscapes. The mapped results show that increasing {\lambda}p expands oscillatory regions toward shorter {\tau}s and moderate-to-long delays, while prominence maps identify parameter regions with the strongest rhythmic coherence. Representative control experiments further connect this global landscape to local rhythm-forming mechanisms, showing that STDP freezing weakens rhythmic coherence whereas delay jitter enhances it with minimal change in mean firing rate. As a result, these findings provide a useful reference for operating-point selection, synchrony modulation studies, and future biologically grounded spiking-network modeling within similar balanced-network settings.