Maternal barbiturate administration and offspring response to shock

Area of Science:

• Neuroscience
• Developmental Toxicology
• Behavioral Pharmacology

Background:

• Maternal exposure to barbiturates during pregnancy can impact offspring neurodevelopment.
• Understanding the long-term effects of specific barbiturates like pentobarbital and phenobarbital is crucial for assessing developmental risks.

Purpose of the Study:

• To investigate the effects of prenatal pentobarbital sodium (PT) and sodium phenobarbital (PH) exposure on offspring development and behavior in Sprague-Dawley rats.
• To assess the impact of these drugs on neonatal viability, activity levels, learning, and memory.

Main Methods:

• Pregnant rats were administered PT or PH (20 or 40 mg/kg) or saline SC twice daily from days 9-21 of gestation.
• Neonatal measures, locomotor activity (3-10 months), and avoidance learning (shuttle box, operant chamber) were assessed.
• Brain:body weight ratios were measured at 1 year of age.

Main Results:

• Sodium phenobarbital (PH) exposure led to reduced maternal weight gain and increased neonatal mortality.
• Offspring exposed to PH exhibited hyperactivity and slower escape responses to shock.
• Pentobarbital (PT) exposure resulted in transient hyperactivity and poorer performance on avoidance tasks.
• Both drugs shifted the sex ratio towards male births; all drug groups showed enhanced performance in punishment paradigms.

Conclusions:

• Prenatal exposure to pentobarbital sodium and sodium phenobarbital induces significant neurodevelopmental and behavioral alterations in rat offspring.
• These effects include hyperactivity, impaired learning, and altered brain development, highlighting potential risks associated with in-utero barbiturate exposure.
• The observed sex ratio shift warrants further investigation into sex-specific developmental impacts.