Brain-organ axis: How does stress regulate peripheral immunity through neural signaling?

Area of Science:

• Neuroimmunology
• Psychoneuroimmunology
• Physiology

Background:

• Behavioral responses to stimuli involve neural circuits and the immune system.
• Bidirectional communication exists between the nervous and peripheral organ systems.
• Stress and immunity interplay is a key area of interdisciplinary research.

Purpose of the Study:

• To introduce and elucidate the "brain-organ axis" concept.
• To explain how the brain responds to psychological stressors.
• To review neuroimmune interactions in stress and psychological disorders.

Main Methods:

• Literature review integrating recent findings on the brain-organ axis.
• Analysis of neuroimmune interaction mechanisms.
• Exploration of stress-induced emotional states and organ-specific immune regulation.

Main Results:

• Psychological stress activates the hypothalamic-pituitary-adrenal axis and sympathetic nervous system, modulating peripheral immunity.
• Stress differentially affects immune cells and tissue microenvironments in organs like skin, gut, liver, heart, spleen, and lungs.
• Peripheral inflammation impacts central nervous system function, creating a neuroimmune regulatory loop.

Conclusions:

• The brain-organ axis framework explains how stress influences organ-specific immune responses.
• Psychological states can drive peripheral inflammation and somatic disease through neuroimmune pathways.
• Understanding these mechanisms is crucial for comprehending the role of psychological factors in systemic immunity.