Late Brain Involvement after Neonatal Immune Activation.

Area of Science:

• Neuroscience
• Immunology
• Developmental Biology

Background:

• The immature neonatal immune system is vulnerable to infections, and immune activation can compromise the blood-brain barrier.
• Neonatal immune activation may trigger central nervous system (CNS) inflammation, affecting behavior and neurochemistry.
• Neuroinflammation is hypothesized to play a role in neurodegenerative diseases like Alzheimer's disease (AD).

Purpose of the Study:

• To investigate the long-term effects of neonatal immune activation on visuospatial memory.
• To assess neuroinflammation by measuring cytokine levels in the hippocampus and cortex.
• To evaluate the expression of tau and GSK-3β proteins in the brain following neonatal endotoxemia.

Main Methods:

• C57BL/6 mice at two days of age received a single lipopolysaccharide (LPS) injection to induce neonatal endotoxemia.
• Visuospatial memory was assessed at 60, 120, and 180 days of age.
• Hippocampus and cortex tissues were analyzed for cytokine levels (TNF-α, IL-1β) and protein expression (GSK-3β, Tau).

Main Results:

• Neonatal LPS exposure resulted in visuospatial memory impairment at 120 and 180 days of age.
• Elevated TNF-α and IL-1β levels were observed in the hippocampus and cortex at 60 days.
• Increased GSK-3β expression was noted in the hippocampus (60, 120, 180 days) and cortex (120, 180 days).
• Tau protein expression was elevated in the hippocampus and cortex at 120 days, and in the hippocampus at 180 days.

Conclusions:

• Neonatal immune activation is associated with lasting visuospatial memory deficits.
• Early-life immune challenges can induce persistent neuroinflammation and alter key protein expressions (GSK-3β, Tau).
• These findings suggest a potential link between neonatal immune activation and long-term neurodegenerative processes.