Systemic inflammation alters satellite glial cell function and structure. A possible contribution to pain

Area of Science:

• Neuroscience
• Immunology
• Pain Research

Background:

• Local peripheral injury activates satellite glial cells (SGCs) in sensory ganglia, potentially contributing to chronic pain.
• The effect of systemic inflammation on sensory ganglia remains less understood.

Purpose of the Study:

• To investigate whether systemic inflammation affects sensory ganglia similarly to local injury.
• To characterize the changes in SGCs and neurons in dorsal root ganglia (DRG) following systemic inflammation.

Main Methods:

• Systemic inflammation induced in mice via intraperitoneal lipopolysaccharide (LPS) injection.
• Characterization of SGCs and neurons using dye injection, calcium imaging, electron microscopy (EM), immunohistochemistry, and electrical recordings.
• Assessment of pain behavior and the effect of gap junction blockade.

Main Results:

• LPS induced SGC activation and increased SGC dye coupling 3-4.5-fold.
• EM revealed abnormal SGC process growth and new gap junction formation.
• Increased SGC sensitivity to ATP, augmented neuronal excitability, and reduced pain behavior upon gap junction blockade were observed.

Conclusions:

• Systemic inflammation induces changes in DRG similar to local injury.
• These DRG changes, including SGC activation and altered neuronal excitability, may explain pain associated with systemic inflammation and disease.