Prenatal nicotine changes the response to postnatal chlorpyrifos: Interactions targeting serotonergic synaptic...

Area of Science:

• Neuroscience
• Developmental Toxicology
• Environmental Health

Background:

• Nicotine and chlorpyrifos are developmental neurotoxicants impacting serotonin systems.
• Prenatal exposure to these agents can have long-term neurological consequences.

Purpose of the Study:

• To investigate the long-term effects of prenatal nicotine exposure on the response to postnatal chlorpyrifos exposure.
• To examine alterations in serotonin receptor expression and turnover in cerebrocortical regions.

Main Methods:

• Pregnant rats received nicotine (3mg/kg/day) throughout gestation.
• Pups were exposed to chlorpyrifos (1mg/kg) on postnatal days 1-4.
• Serotonin receptor expression and turnover were measured from adolescence (PN30) to adulthood (PN150).

Main Results:

• Individual nicotine or chlorpyrifos exposure increased serotonin receptor expression and turnover, with sex-specific patterns.
• Combined exposure reduced or reversed these adaptive changes and dissipated normal sex differences.
• Behavioral tests confirmed alterations in neurochemical responses.

Conclusions:

• Prenatal nicotine exposure can heighten vulnerability to neurotoxic chemicals like chlorpyrifos.
• Combined exposures disrupt normal neurodevelopmental trajectories and sex-specific adaptations in serotonin systems.
• These findings highlight additional risks beyond known liabilities of maternal smoking during pregnancy.