Fluctuation-driven rhythmogenesis in an excitatory neuronal network with slow adaptation

Area of Science:

• Computational neuroscience
• Theoretical neuroscience
• Network dynamics

Background:

• Spiking neural networks exhibit complex dynamics influenced by synaptic noise and intrinsic neuronal properties.
• Activity-dependent currents, like hyperpolarization, play a crucial role in shaping neuronal firing patterns.
• Understanding noise-induced oscillations is key to comprehending neural computation and network robustness.

Purpose of the Study:

• To investigate the role of noise in inducing and controlling burst oscillations in a network of spiking neurons.
• To analyze how synaptic background noise and cell excitability affect the robustness and frequency of rhythmic bursting.
• To reduce the complex network dynamics to low-dimensional mean field equations for analytical insights.

Main Methods:

• Simulating an excitatory all-to-all coupled network of N spiking neurons.
• Incorporating synaptically filtered background noise and slow activity-dependent hyperpolarization currents.
• Utilizing a separation of time scales to derive mean field equations in the limit of large N.
• Analyzing the bifurcation structure of the derived mean field equations.

Main Results:

• The system exhibits noise-induced burst oscillations across a range of noise strengths and cell excitability levels.
• Noise enhances the robustness of rhythmic bursting and expands the range of achievable burst frequencies.
• Low-dimensional mean field equations accurately capture the network dynamics for large N.
• Bifurcation analysis reveals the mechanisms underlying burst initiation and termination.

Conclusions:

• Noise is not merely a disruptive factor but can be a crucial mechanism for enhancing functional properties in neural networks.
• The developed mean field model provides a powerful tool for understanding the collective dynamics of spiking neural networks.
• This work offers insights into how neural systems can achieve robust and flexible rhythmic activity through noise modulation.