A Two‑Axis Integrative Model of Peripheral Inflammatory Signaling, Trigeminal Activation, and Brain Network Modulation

Peripheral inflammatory signals arising from the gastrointestinal tract and the nasopharyngeal barrier can influence central nervous system reactivity through convergent pathways involving systemic cytokines, blood–brain barrier permeability, trigeminal sensory input, and microglial activation. This manuscript proposes a unified two‑axis conceptual model describing how (A) colon‑derived LPS flux and (B) nasopharyngeal inflammatory dynamics interact to modulate brain networks responsible for attention, emotional regulation, executive function, and sensory processing. The model integrates physiological mechanisms across multiple systems and outlines a framework for understanding how peripheral signals may shape central neural states.