Prenatal cannabis exposure had long-lasting and significant effects on cognitive and memory functions, a new rodent model study found. Surprisingly, these effects are sex-specific, implying that cannabis exposure in the womb affects males and females differently.
Previous studies have shown that prenatal cannabis exposure can hinder a fetus’s normal growth, but it is still unclear how long-term effects on brain development will manifest. Researchers are now shedding new light on this topic and suggesting potential actions to address the negative effects.
“Over the past two decades, concentrations of THC — the primary psychoactive component in cannabis — have risen from 3% to 22%. THC can pass through the placenta and impact the developing fetal brain. Our research shows that prenatal THC exposure can lead to serious cognitive and memory deficits that are sex-dependent, enduring and potentially lifelong,”
said Mohammed H. Sarikahya, one of the study’s leaders.
Endocannabinoid System Disruption
The research team used a range of tests, such as social interaction, spontaneous alternation, and object recognition tests, to gauge the effects of prenatal THC exposure on animal models. These evaluations demonstrated that prenatal THC exposure had a significant impact on both males and female offspring’s social desire, memory of prior social interactions, and learning abilities.
THC disrupts the fetal endocannabinoid system (ECS), which is important in fetal and adolescent neurodevelopment, as well as cognitive and emotional processing, according to the researchers.
“This disruption leads to deficiencies in vital fatty acids like DHA and ARA, potentially causing lifelong health disturbances,”
said co-leader Steven Laviolette, professor in the anatomy and cell biology department at Schulich Medicine & Dentistry.
Ventral Hippocampus Activity
The study offers a potential way to alleviate these effects. It might be possible to lessen the negative effects of prenatal cannabis exposure by focusing on abnormalities in the brain’s fatty acid composition.
When the researchers looked more closely at the molecular effects, they discovered variations in the levels of specific proteins and important fatty acids in the brain, both essential for healthy brain function. These changes varied depending on the particular area of the brain and were more pronounced in adult males.
The study emphasizes how prenatal cannabis exposure affects males and females differently. Both male and female offspring exhibited cognitive deficits, but the underlying causes were very different in the two sexes.
The study discovered that females had very active brain activity in a region of the brain known as the ventral hippocampus. The ventral hippocampus is a part of the brain involved in emotions and memory.
Males, on the other hand, had less active brain activity in this same area.
“This suggests prenatal cannabis exposure can have sex-specific effects on the developing brain, leading to different patterns of cognitive and behavioral disturbances in males and females,”
- Sarikahya, M. H., Cousineau, S. L., De Felice, M., Szkudlarek, H. J., Wong, K. K. W., DeVuono, M. V., Lee, K., Rodríguez-Ruiz, M., Gummerson, D., Proud, E., Ng, T. H. J., Hudson, R., Jung, T., Hardy, D. B., Yeung, K. K., Schmid, S., Rushlow, W., & Laviolette, S. R. (2023). Prenatal THC exposure induces long-term, sex-dependent cognitive dysfunction associated with lipidomic and neuronal pathology in the prefrontal cortex-hippocampal network. Molecular psychiatry, 10.1038/s41380-023-02190-0.