Sociability: Comparing the Effect of Chlorpyrifos with Valproic Acid

Area of Science:

• Neuroscience
• Toxicology
• Developmental Biology

Background:

• Organophosphate pesticides, like chlorpyrifos (CPF), are increasingly investigated for potential links to autism spectrum disorder (ASD).
• Valproic acid (VPA) administration during gestation is an established method for creating animal models of autism.

Purpose of the Study:

• To investigate whether prenatal exposure to chlorpyrifos (CPF) in Wistar rats induces behavioral phenotypes comparable to those observed in valproic acid (VPA)-induced autism models.
• To assess the impact of prenatal CPF exposure on sociability and social novelty in adolescent and adult rats.

Main Methods:

• Wistar rats were exposed prenatally to chlorpyrifos (CPF, 1 mg/kg) or valproic acid (VPA, 400 mg/kg) during specific gestational days (GD 12.5-15.5).
• The three-chambered social interaction test was used to evaluate sociability and reaction to social novelty in two experimental phases: adolescence and adulthood.
• Behavioral data from CPF and VPA exposed groups were compared against a control group (CNT).

Main Results:

• Animals exposed prenatally to either CPF or VPA exhibited a distinct behavioral phenotype compared to the control group.
• In adolescence, CPF-exposed rats displayed a negative index for reaction to social novelty, a pattern also observed, though less pronounced, in VPA-exposed rats.
• Both CPF and VPA experimental groups demonstrated a recovery in the reaction to social novelty during adulthood.

Conclusions:

• Prenatal exposure to chlorpyrifos (CPF) in rats can induce behavioral changes in social interaction, particularly concerning social novelty.
• The behavioral effects observed in CPF-exposed rats share similarities with established valproic acid (VPA) animal models of autism spectrum disorder.
• These findings suggest a potential role for prenatal organophosphate pesticide exposure in altering social behaviors relevant to autism.