Adolescent rats exposed to THC prenatally showed sex-specific spatial memory impairments, with males more severely affected and showing reduced inhibitory interneurons in the hippocampus.
People interested in prenatal cannabis exposure and its potential effects on brain development.
Males lost inhibitory interneurons; females gained them
What the researchers found
Prenatal THC exposure caused sex-specific disruption in spatial memory retrieval and flexibility. Males showed decreased density of CCK-positive basket cells (inhibitory interneurons) and increased neuroplasticity markers. Females showed delayed memory retrieval but preserved flexibility, increased CCK+BC density, and mostly preserved neuroplasticity markers.
Why it matters
This study provides biological mechanisms for why prenatal cannabis exposure might affect brain development differently in males and females, specifically through disruption of the excitatory/inhibitory balance in the hippocampus.
The numbers in context
THC dose: 2 mg/kg daily. Exposure period: gestational days 5-20. Males showed decreased CCK+BC density. Females showed increased CCK+BC density. Changes in neuroligin-1 and neuroligin-3 isoforms were observed in both sexes.
How the study worked
Sprague Dawley dams received THC (2 mg/kg) or vehicle from gestational day 5-20. Adolescent offspring were tested in the Barnes Maze for spatial memory. Hippocampal tissue was analyzed for CCK+BC density, neuroplasticity gene expression, and neuroligin isoform expression.
What this study cannot tell us
Animal model using a single THC dose that may not reflect typical human prenatal exposure patterns. Rats were exposed throughout most of gestation, while human exposure patterns vary. Adolescent testing only, so long-term adult outcomes are unknown.
How to read the evidence
Well-designed animal study with multiple biological endpoints and both sexes. THC dose and exposure timing are controlled, though translation to human prenatal exposure requires caution.
When this study was published
Published in 2024 in Biomedicine & Pharmacotherapy.
The bigger picture
With prenatal cannabis exposure increasing alongside legalization, understanding sex-specific developmental effects is critical. The finding that males and females show opposite changes in inhibitory interneuron density suggests fundamentally different biological responses to prenatal THC.
Questions still open
- Do human studies show similar sex-specific patterns in children prenatally exposed to cannabis? Are the increased CCK+BCs in females protective or a separate kind of disruption? Would lower THC doses produce similar sex-dependent effects?
Common questions
Does prenatal cannabis affect boys and girls differently?
What part of the brain was affected?
Read the original research
Prenatal THC exposure drives sex-specific alterations in spatial memory and hippocampal excitatory/inhibitory balance in adolescent rats.
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, 181, 117699
Citation
Castelli, Valentina; Lavanco, Gianluca; Tringali, Giuseppe; D'Amico, Cesare; Feo, Salvatore; Di Bartolomeo, Martina; D'Addario, Claudio; Kuchar, Martin; Brancato, Anna; Cannizzaro, Carla. (2024). Prenatal THC exposure drives sex-specific alterations in spatial memory and hippocampal excitatory/inhibitory balance in adolescent rats.. Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie, 181, 117699. https://doi.org/10.1016/j.biopha.2024.117699
Explore the wider topic
- How to Talk to Your Teenager About Weed (Without Losing Them)
- My Kid's Friends Smoke Weed: A Parent's Guide
- I Smoke Weed But Don't Want My Kids To: Navigating the Hypocrisy
- Quitting Weed as a Parent: Why It Is the Hardest and Most Important Quit
- Quitting Weed as a Teen or Young Adult
- My Kid Is Smoking Weed: A Parent's Guide