Vagus nerve stimulation as a predictive coding modulator that enhances feedforward over feedback transmission

Area of Science:

• Neuroscience
• Computational Neuroscience
• Systems Neuroscience

Background:

• Vagus nerve stimulation (VNS) shows therapeutic potential for epilepsy, depression, and stroke rehabilitation.
• The precise neural mechanisms underlying VNS efficacy remain incompletely understood.
• Existing research lacks a unified framework to explain VNS effects on neural circuits.

Purpose of the Study:

• To propose a novel theoretical framework for understanding VNS mechanisms of action.
• To conceptualize VNS effects through the lens of predictive coding and neural circuit modulation.
• To integrate anatomical, physiological, and neuromodulatory evidence to explain VNS influence on neural dynamics.

Main Methods:

• Development of a theoretical framework based on predictive coding principles.
• Integration of evidence from anatomical pathways, receptor distributions, and physiological responses.
• Analysis of VNS effects on feedforward and feedback neural circuit processing.

Main Results:

• VNS is proposed to shift the balance between feedforward and feedback processing, enhancing feedforward signal transmission.
• Acetylcholine and noradrenaline (norepinephrine) are identified as key neuromodulators differentially affecting feedforward and feedback signaling.
• The framework explains VNS influence on neural dynamics across various spatial and temporal scales.

Conclusions:

• VNS may facilitate neural plasticity and adaptive behaviors by modulating feedforward and feedback signaling.
• This predictive coding framework offers a unified perspective on circuit-specific VNS effects.
• The proposed mechanisms provide a basis for interpreting cognitive and therapeutic outcomes of VNS and suggest future research directions.