Bistability, Causality, and Complexity in Cortical Networks: An In Vitro Perturbational Study

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Spatiotemporal complexity of cortical responses to perturbations is a reliable index of consciousness capacity in humans.
• Loss of consciousness is associated with a collapse of complex causal interactions into slow waves, suggesting a role for cortical bistability.
• Cortical bistability manifests as slow oscillations, a default activity pattern in disconnected networks.

Purpose of the Study:

• To investigate the relationship between bistability and complexity in cortical circuits using an in vitro model.
• To adapt and apply the perturbational complexity index (PCI) at a microscale level.
• To gain mechanistic insights into macroscale consciousness measurements in humans.

Main Methods:

• Utilized an in vitro model of electrically stimulated cortical slices.
• Adapted the human perturbational complexity index (PCI) for use in cortical slices.
• Manipulated neuromodulatory conditions to alter bistability and excitability.

Main Results:

• Demonstrated that perturbational complexity in cortical slices is modulated by pharmacological reduction of bistability.
• Showed that enhancement of excitability also affects perturbational complexity, though to a lesser extent.
• Provided mechanistic insights linking microscale bistability to macroscale complexity measurements.

Conclusions:

• Cortical bistability plays a significant role in determining the complexity of neural responses.
• The in vitro model effectively replicates and provides mechanistic understanding for macroscale observations of consciousness.
• Perturbational complexity is a viable measure for assessing brain states at both micro and macro levels.