Sub-threshold neuronal activity and the dynamical regime of cerebral cortex

Area of Science:

• Neuroscience
• Computational Neuroscience

Background:

• Cortical neurons display irregular spiking and varied firing rates.
• These patterns are linked to fluctuation-driven regimes in model circuits.
• The operation of the cortex in this regime remains debated.

Purpose of the Study:

• To test the fluctuation-driven hypothesis in the frontal cortex during decision-making.
• To investigate the role of neuronal morphology in cortical function.

Main Methods:

• Analysis of spiking and sub-threshold membrane potentials in mouse frontal cortex neurons.
• Evaluation of standard fluctuation-driven models.
• Incorporation of dendritic morphology into neuronal models.

Main Results:

• Standard models capture spiking statistics but not sub-threshold heterogeneity.
• Dendritic morphology inclusion enhanced neuronal selectivity.
• Dendritic morphology inclusion reduced error trials during decision-making.

Conclusions:

• Cortical neurons in higher-order areas operate in a fluctuation-driven regime during decision-making.
• Dendritic morphology plays a functional role in decision-making.
• Standard single-compartment models are insufficient to capture cortical dynamics.