Prenatal THC Exposure Altered Fetal Brain Development in Rhesus Monkeys
Daily THC edible exposure throughout pregnancy in rhesus macaques was associated with significant alterations in fetal brain growth, histological changes, and molecular dysregulation of axonal guidance pathways.
Quick Facts
What This Study Found
THC exposure was associated with significant age-by-sex interactions in brain volumetric growth on MRI, differences in fetal brain histology suggestive of dysregulation, and two extracellular vesicle-associated miRNAs in fetal CSF linked to dysregulated axonal guidance and netrin signaling pathways.
Key Numbers
n=5 per group; daily THC edibles from pre-conception through pregnancy; 4 MRI timepoints; 2 miRNAs identified in fetal CSF; pathway analysis linked to axonal guidance and netrin signaling.
How They Did This
Rhesus macaques received daily THC edibles pre-conception through pregnancy (n=5 THC, n=5 control). Fetal MRI at gestational days 85, 110, 135, and 155. Cesarean delivery at G155 with collection of CSF for miRNA analysis and tissue for histology.
Why This Research Matters
This is one of the first studies to use a primate model with THC edibles, closely approximating human exposure patterns. The convergence of MRI, histological, and molecular findings strengthens the evidence that prenatal THC disrupts neurodevelopment.
The Bigger Picture
Rhesus macaque brain development is far more similar to human than rodent models. The identification of specific molecular pathways (axonal guidance, netrin signaling) gives mechanistic insight into how THC may alter fetal brain wiring.
What This Study Doesn't Tell Us
Small sample (n=5 per group). Cannot determine long-term neurodevelopmental outcomes from fetal measures. THC edible dose may not match typical human consumption. No assessment of postnatal behavior.
Questions This Raises
- ?Do the axonal guidance disruptions persist into postnatal brain development?
- ?Are the sex-specific effects on brain growth clinically significant in human pregnancies?
Trust & Context
- Key Stat:
- THC disrupted axonal guidance pathways in primate fetal brains
- Evidence Grade:
- Primate model with multi-modal assessment (MRI + histology + molecular), limited by small sample size.
- Study Age:
- 2024 publication
- Original Title:
- Prenatal delta-9-tetrahydrocannabinol exposure alters fetal neurodevelopment in rhesus macaques.
- Published In:
- Scientific reports, 14(1), 5808 (2024)
- Authors:
- Ryan, Kimberly S(3), Karpf, Joshua A, Chan, Chi Ngai, Hagen, Olivia L, McFarland, Trevor J, Urian, J Wes, Wang, Xiaojie, Boniface, Emily R, Hakar, Melanie H, Terrobias, Jose Juanito D, Graham, Jason A, Passmore, Scarlet, Grant, Kathleen A, Sullivan, Elinor L, Grafe, Marjorie R, Saugstad, Julie A, Kroenke, Christopher D, Lo, Jamie O
- Database ID:
- RTHC-05676
Evidence Hierarchy
Frequently Asked Questions
Does THC affect fetal brain development?
In this rhesus macaque study, daily THC edibles from pre-conception through pregnancy altered fetal brain growth patterns on MRI, produced histological changes, and disrupted molecular pathways involved in brain wiring. These are primate data more relevant to humans than rodent studies.
How does prenatal THC affect the developing brain?
This study identified two specific miRNAs in fetal cerebrospinal fluid linked to disrupted axonal guidance and netrin signaling, pathways critical for brain wiring during development. The histological findings were consistent with these molecular changes.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-05676APA
Ryan, Kimberly S; Karpf, Joshua A; Chan, Chi Ngai; Hagen, Olivia L; McFarland, Trevor J; Urian, J Wes; Wang, Xiaojie; Boniface, Emily R; Hakar, Melanie H; Terrobias, Jose Juanito D; Graham, Jason A; Passmore, Scarlet; Grant, Kathleen A; Sullivan, Elinor L; Grafe, Marjorie R; Saugstad, Julie A; Kroenke, Christopher D; Lo, Jamie O. (2024). Prenatal delta-9-tetrahydrocannabinol exposure alters fetal neurodevelopment in rhesus macaques.. Scientific reports, 14(1), 5808. https://doi.org/10.1038/s41598-024-56386-7
MLA
Ryan, Kimberly S, et al. "Prenatal delta-9-tetrahydrocannabinol exposure alters fetal neurodevelopment in rhesus macaques.." Scientific reports, 2024. https://doi.org/10.1038/s41598-024-56386-7
RethinkTHC
RethinkTHC Research Database. "Prenatal delta-9-tetrahydrocannabinol exposure alters fetal ..." RTHC-05676. Retrieved from https://rethinkthc.com/research/ryan-2024-prenatal-delta9tetrahydrocannabinol-exposure-alters
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.