Short-term synaptic plasticity in the deterministic Tsodyks-Markram model leads to unpredictable network dynamics

Abstract

Short-Term Synaptic Plasticity (STSP) strongly affects the neural dynamics of cortical networks. The Tsodyks and Markram (TM) model for STSP accurately accounts for a wide range of physiological responses at different types of cortical synapses. Here, we report for the first time a route to chaotic behavior via a Shilnikov homoclinic bifurcation that dynamically organises some of the responses in the TM model. In particular, the presence of such a homoclinic bifurcation strongly affects the shape of the trajectories in the phase space and induces highly irregular transient dynamics; indeed, in the vicinity of the Shilnikov homoclinic bifurcation, the number of population spikes and their precise timing are unpredictable and highly sensitive to the initial conditions. Such an irregular deterministic dynamics has its counterpart in stochastic/network versions of the TM model: the existence of the Shilnikov homoclinic bifurcation generates complex and irregular spiking patterns and --acting as a sort of springboard-- facilitates transitions between the down-state and unstable periodic orbits. The interplay between the (deterministic) homoclinic bifurcation and stochastic effects may give rise to some of the complex dynamics observed in neural systems.

Published in PNAS (Early edition) sept. 2013

References in corpus (3)

• Emergent complex neural dynamics
• How Chaotic is the Balanced State?
• The effect of neural adaptation of population coding accuracy

Cited by in corpus (12)

• Exact neural mass model for synaptic-based working memory
• Self-organized bistability and its possible relevance for brain dynamics
• Positive Feedback and Synchronized Bursts in Neuronal Cultures
• Failure of neuron network coherence induced by SARS-CoV-2-infected astrocytes
• Rhythmogenesis in the mean field model of the neuron-glial network
• Chaos and correlated avalanches in excitatory neural networks with synaptic plasticity
• Framework for global stability analysis of dynamical systems
• Ordered intricacy of Shilnikov saddle-focus homoclinics in symmetric systems
• A Rich Spectrum of Neural Field Dynamics in the Presence of Short-Term Synaptic Depression
• Adaptive Synchronization and Anticipatory Dynamical System
• Renewal Approach to the Analysis of the Asynchronous State for Coupled Noisy Oscillators
• Complex activity patterns generated by short-term synaptic plasticity