Prefrontal oscillations modulate the propagation of neuronal activity required for working memory

Area of Science:

• Computational Neuroscience
• Cognitive Neuroscience
• Systems Neuroscience

Background:

• Cognition relies on working memory (WM) to guide actions, requiring selective gating of information.
• Prefrontal cortex (PFC) plays a crucial role in cognitive control and information gating.
• Network oscillations are implicated in neural communication and cognitive functions.

Purpose of the Study:

• To explore the hypothesis that PFC network oscillations, using local inhibition, can independently gate responses to WM items.
• To investigate the role of local inhibition in controlling spike bursts and generating oscillatory responses.
• To understand how network resonance and excitability influence signal propagation for cognitive tasks.

Main Methods:

• Utilized biophysically-detailed modeling to simulate neural network dynamics in the PFC.
• Investigated the effect of varying deep layer principal cell excitability on network resonant frequency.
• Analyzed the relationship between oscillation period, signal propagation, and WM content.

Main Results:

• Local inhibition controls spike burst periods and produces oscillatory responses regardless of WM item state (asynchronous or oscillatory).
• WM items inducing faster oscillatory population responses in the PFC output layer were propagated more reliably.
• Network resonant frequency of the output layer is tunable by altering deep layer principal cell excitability.

Conclusions:

• PFC network oscillations, modulated by local inhibition and network resonance, provide a mechanism for flexible gating of WM outputs.
• Adjusting network excitability dynamically tunes the resonant frequency, enabling selection of specific signals (asynchronous or oscillatory).
• This provides a dynamic mechanism for governing signal propagation throughout the neocortex, supporting cognitive processes like rule-based action selection.