Immune cells and CNS physiology: Microglia and beyond

Area of Science:

• Neuroscience
• Immunology
• Neuroimmunology

Background:

• The immune system's role extends beyond "self" vs. "nonself" to maintaining organ homeostasis.
• The central nervous system (CNS) exhibits a unique immune segregation between the brain parenchyma and meningeal spaces.

Purpose of the Study:

• To review the specialized immune landscape of the CNS.
• To explore the functional implications of the partition between brain parenchyma and meningeal immunity.
• To re-evaluate the role of meningeal immunity in CNS function and homeostasis.

Main Methods:

• Review of recent scientific literature on CNS immunity.
• Analysis of the distinct immune cell populations in the brain parenchyma and meningeal spaces.
• Synthesis of current understanding regarding neuro-immune crosstalk.

Main Results:

• The brain parenchyma is patrolled by microglia and perivascular macrophages.
• Meningeal spaces harbor a diverse immune cell repertoire.
• The segregation of immune cells allows for finely tuned neuro-immune crosstalk.

Conclusions:

• The partition of immunity within the CNS is crucial for optimal neuro-immune communication.
• Meningeal immunity, rather than being a threat, actively contributes to CNS health and performance.
• Emerging evidence highlights the supportive role of meningeal immunity in maintaining central nervous system homeostasis.