Prenatal alcohol and tetrahydrocannabinol exposure: Effects on spatial and working memory

Area of Science:

• Neuroscience
• Developmental Psychology
• Pharmacology

Background:

• Alcohol and cannabis are common recreational drugs with known risks to fetal development.
• Simultaneous use of alcohol and cannabis during pregnancy is prevalent but its effects on fetal development are poorly understood.
• Prenatal exposure to these substances can lead to cognitive impairments in offspring.

Purpose of the Study:

• To investigate the effects of prenatal exposure to ethanol (EtOH), Δ-9-tetrahydrocannabinol (THC), or their combination on spatial and working memory in an animal model.
• To determine if combined exposure exacerbates the negative impacts of individual substances on cognitive development.
• To explore sex-specific differences in the effects of prenatal substance exposure.

Main Methods:

• Pregnant Sprague-Dawley rats were exposed to vaporized ethanol, THC, the combination, or vehicle control during gestational days 5-20.
• Adolescent male and female offspring were assessed using the Morris water maze task.
• Spatial and working memory performance was evaluated.

Main Results:

• Prenatal THC exposure impaired spatial learning and memory in female offspring.
• Prenatal EtOH exposure impaired working memory in offspring.
• Combined EtOH and THC exposure did not worsen individual effects but led to reduced thigmotaxis, suggesting increased risk-taking behavior.

Conclusions:

• Prenatal exposure to THC and EtOH has differential, substance- and sex-specific effects on cognitive and emotional development.
• These findings underscore the potential harm of cannabis and alcohol use during pregnancy.
• The results support public health initiatives to reduce alcohol and cannabis consumption by pregnant individuals.