Network bistability mediates spontaneous transitions between normal and pathological brain states

Area of Science:

• Neuroscience
• Computational Neuroscience
• Epilepsy Research

Background:

• Cortical networks display diverse activity patterns, including physiological and pathological states.
• Epileptic brain activity, characterized by hyperactivity, presents a complex dynamic repertoire.
• Understanding the mechanisms underlying these different network states is crucial.

Purpose of the Study:

• To investigate how cortical networks generate distinct physiological and pathological activity patterns.
• To explore the coexistence of normal and seizure-like activity within the same network.
• To identify factors influencing transitions between these network states.

Main Methods:

• Development of a realistic computational model of cortical networks.
• Simulation of network dynamics under varying afferent input levels.
• Analysis of network state transitions triggered by transient perturbations.

Main Results:

• Physiological sparse activity and pathological tonic-clonic activity can coexist in the same network at identical input levels.
• Transient input perturbations can switch the network between stable physiological and pathological states.
• Potassium regulation effectiveness influences physiological state stability and seizure initiation threshold.

Conclusions:

• Cortical networks exhibit intrinsic multistability, allowing for coexistence of different dynamic regimes.
• Pathological brain activity may arise from intrinsic network properties rather than solely dynamic instabilities.
• Network state transitions are influenced by intrinsic stability and regulatory mechanisms, not just external conditions.