Adolescent experience affects postnatal ultrasonic vocalizations and gene expression in future offspring

Area of Science:

• Neuroscience
• Developmental Psychology
• Behavioral Genetics

Background:

• Adolescent experiences can impact maternal behavior and offspring development.
• Maternal separation elicits ultrasonic vocalizations (USVs) in offspring, reflecting distress.
• Opioid and dopamine systems are crucial for regulating USVs and social behaviors.

Purpose of the Study:

• To investigate the effects of maternal adolescent morphine exposure on offspring's postnatal ultrasonic vocalizations (USVs) and gene expression.
• To examine changes in communication and attachment behaviors in offspring due to prenatal opioid exposure.
• To assess the role of dopamine D2 receptor and mu opioid receptor (oprm1) mRNA in the nucleus accumbens and hypothalamus.

Main Methods:

• Assessed separation-induced distress calls and maternal potentiation of distress calls in offspring.
• Measured relative mRNA expression of dopamine D2 receptor and oprm1 in the nucleus accumbens and hypothalamus.
• Utilized Sprague-Dawley rats with maternal exposure to morphine, saline, or no handling during adolescence.

Main Results:

• Maternal adolescent morphine exposure led to region-specific gene expression differences in offspring.
• Offspring exhibited a reduced number of separation-induced distress calls.
• Augmented maternal potentiation of distress calls was observed exclusively in offspring of morphine-exposed mothers.

Conclusions:

• Adolescent maternal morphine exposure has lasting effects on offspring's communication and neurobiology.
• Gene expression in the nucleus accumbens and hypothalamus is altered, correlating with behavioral changes.
• Maternal potentiation of offspring distress calls is specifically enhanced, suggesting altered maternal caregiving responses.