Electromagnetic pulse activated brain microglia via the p38 MAPK pathway

Area of Science:

• Neuroscience
• Immunology
• Biophysics

Background:

• Electromagnetic pulses (EMP) can increase blood-brain barrier permeability, leading to albumin leakage into brain tissue.
• Albumin is known to activate microglia, suggesting a potential link between EMP exposure and microglia activation.

Purpose of the Study:

• To investigate whether EMP exposure activates microglia in the rat brain.
• To examine the effects of EMP exposure on microglia morphology, secretory function, and associated signaling pathways.

Main Methods:

• Rats were exposed to EMP (200kV/m, 200 pulses).
• Microglia activation marker (OX-42) and cytokine levels (TNF-α, IL-10, IL-1β, NO) were measured.
• Protein and phosphorylated protein levels of p38, JNK, and ERK signaling pathways were analyzed.
• The effect of a p38 inhibitor (SB203580) on EMP-induced changes was assessed.

Main Results:

• EMP exposure significantly increased OX-42 expression, indicating microglia activation.
• Levels of nitric oxide (NO), TNF-α, and IL-10 were significantly altered post-EMP exposure.
• p38 pathway proteins (total and phosphorylated) increased significantly after EMP exposure.
• Inhibition of p38 partly prevented EMP-induced changes in cytokine and NO levels.

Conclusions:

• EMP exposure activates microglia in the rat brain and affects their secretory function.
• The p38 signaling pathway plays a role in EMP-induced microglia activation and the subsequent inflammatory response.