Systemic inflammation disrupts the developmental program of white matter.

Area of Science:

• Neuroscience
• Developmental Biology
• Inflammation Research

Background:

• Perinatal inflammation is a significant risk factor for neurological deficits in preterm infants.
• Systemic inflammation can disrupt developing brain programming, but detailed mechanisms remain unclear.
• Previous studies used severe stimuli, not reflecting moderate inflammation in human infants.

Purpose of the Study:

• To investigate if moderate systemic inflammation alters white matter development.
• To test the hypothesis that interleukin-1β (IL-1β) exposure impacts brain development.

Main Methods:

• Newborn mice received twice-daily intraperitoneal injections of IL-1β for 5 days.
• Assessed myelination, oligodendrogenesis, behavior, and used magnetic resonance imaging (MRI).

Main Results:

• IL-1β exposure caused long-lasting myelination defects, including more nonmyelinated axons and reduced myelinated axon diameter.
• Observed reduced myelinating oligodendrocytes and increased oligodendrocyte progenitors, indicating maturation blockade.
• Abnormalities correlated with reduced white matter fractional anisotropy (MRI) and memory deficits.

Conclusions:

• Moderate perinatal systemic inflammation alters white matter developmental programming.
• This insult leads to persistent myelination deficits, cognitive impairments, and MRI abnormalities.
• Findings support the clinical relevance of moderate inflammation in preterm infant brain development.