Prenatal lipopolysaccharide reduces social behavior in male offspring

Area of Science:

• Neuroscience
• Developmental Biology
• Behavioral Science

Background:

• Maternal immune activation during pregnancy is linked to neurodevelopmental and behavioral outcomes in offspring.
• Sickness behavior in the dam, a response to infection or inflammation, may serve as an indicator of prenatal stress exposure.

Purpose of the Study:

• To investigate the impact of maternal sickness behavior induced by lipopolysaccharide (LPS) on the developmental and behavioral trajectory of male offspring.
• To determine if prenatal exposure to LPS affects social interaction, play behavior, and anxiety-like behaviors in male rats.

Main Methods:

• Pregnant Wistar rats received an intraperitoneal injection of lipopolysaccharide (LPS) on gestation day 9.5.
• Offspring were evaluated for physical development, play behavior, social interaction, anxiety-like behavior (plus maze), and brain morphology.
• Maternal sickness behavior, including activity and weight changes, was monitored.

Main Results:

• LPS administration reduced maternal activity, food intake, and weight gain without inducing fever.
• Offspring exhibited reduced play behavior and decreased adult social interaction.
• No significant differences were observed in litter size, physical development, anxiety-like behavior, or brain morphology between groups.

Conclusions:

• Prenatal exposure to LPS, mimicking maternal sickness behavior, negatively impacts male offspring's social behavior from infancy through adulthood.
• These behavioral deficits may stem from altered motivational states or increased anxiety in the offspring.
• The findings highlight the critical role of the prenatal environment in shaping offspring social behavior and emotional regulation.