Prenatal cannabis exposure reduced dopamine D2 receptors in offspring brains through lasting genetic changes
Prenatal cannabis exposure decreased dopamine D2 receptor expression in the human fetal brain's reward center, and in rats, THC exposure during pregnancy produced lasting epigenetic changes that reduced D2 receptors and increased opiate sensitivity in adult offspring.
Quick Facts
What This Study Found
This study combined human fetal tissue analysis with a rat model to investigate how prenatal cannabis exposure affects the developing brain's reward system.
In human fetal subjects, prenatal cannabis exposure specifically decreased dopamine D2 receptor (DRD2) gene expression in the nucleus accumbens, the brain's key reward region. Other dopamine and opioid genes were not significantly affected by cannabis (though cigarettes affected prodynorphin and alcohol affected multiple genes).
In rats, prenatal THC exposure produced epigenetic changes at the D2 receptor gene that persisted into adulthood. Specifically, repressive epigenetic marks increased while activating marks decreased at the DRD2 gene locus. Adult offspring had fewer D2 receptor binding sites and were more sensitive to opiate reward.
This was direct evidence that prenatal cannabis exposure could alter gene regulation through epigenetic mechanisms, with lasting consequences for addiction vulnerability.
Key Numbers
THC dose: 0.15 mg/kg during pregnancy. DRD2 mRNA decreased in human fetal nucleus accumbens. Increased 2meH3K9 (repressive) and decreased 3meH3K4 (activating) marks at Drd2 gene in adult rat offspring. Reduced D2R binding sites and increased opiate sensitivity.
How They Did This
Combined human fetal tissue study and rat model. Human: gene expression analysis in striatal tissue from cannabis-exposed (and cigarette/alcohol-exposed) fetuses. Rat: pregnant rats exposed to THC (0.15 mg/kg), offspring assessed at postnatal day 2 and adulthood by chromatin immunoprecipitation, receptor binding assays, and opiate reward sensitivity tests.
Why This Research Matters
This was among the first studies to demonstrate a specific epigenetic mechanism by which prenatal cannabis exposure could permanently alter reward circuit development and increase addiction vulnerability in offspring.
The Bigger Picture
The epigenetic mechanism provided a molecular explanation for epidemiological observations linking prenatal cannabis exposure to increased substance use vulnerability in children and adolescents.
What This Study Doesn't Tell Us
Human fetal tissue sample sizes were not reported in the abstract. Rat THC doses may not reflect typical human cannabis exposure during pregnancy. Epigenetic changes are complex and other genes may also be affected.
Questions This Raises
- ?Are these epigenetic changes reversible, or are they permanent?
- ?Would they also increase vulnerability to cannabis addiction specifically, or only to opiates?
Trust & Context
- Key Stat:
- Prenatal cannabis altered D2 receptor gene regulation through lasting epigenetic changes
- Evidence Grade:
- Translational study combining human fetal tissue data with a mechanistic rat model, published in Biological Psychiatry.
- Study Age:
- Published in 2011. Epigenetic effects of prenatal cannabis exposure have continued to be investigated.
- Original Title:
- Maternal cannabis use alters ventral striatal dopamine D2 gene regulation in the offspring.
- Published In:
- Biological psychiatry, 70(8), 763-769 (2011)
- Authors:
- DiNieri, Jennifer A(3), Wang, Xinyu, Szutorisz, Henrietta(7), Spano, Sabrina M, Kaur, Jasbir, Casaccia, Patrizia, Dow-Edwards, Diana, Hurd, Yasmin L
- Database ID:
- RTHC-00480
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Can using cannabis during pregnancy affect the baby's brain?
This study found that prenatal cannabis exposure reduced dopamine D2 receptors in the human fetal brain's reward center. In rats, prenatal THC produced lasting genetic changes that made offspring more vulnerable to addiction.
What are epigenetic changes?
Epigenetic changes modify how genes are read without changing the DNA sequence itself. In this study, prenatal THC altered chemical marks on the DNA packaging near the D2 receptor gene, permanently reducing its expression in offspring.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-00480APA
DiNieri, Jennifer A; Wang, Xinyu; Szutorisz, Henrietta; Spano, Sabrina M; Kaur, Jasbir; Casaccia, Patrizia; Dow-Edwards, Diana; Hurd, Yasmin L. (2011). Maternal cannabis use alters ventral striatal dopamine D2 gene regulation in the offspring.. Biological psychiatry, 70(8), 763-769. https://doi.org/10.1016/j.biopsych.2011.06.027
MLA
DiNieri, Jennifer A, et al. "Maternal cannabis use alters ventral striatal dopamine D2 gene regulation in the offspring.." Biological psychiatry, 2011. https://doi.org/10.1016/j.biopsych.2011.06.027
RethinkTHC
RethinkTHC Research Database. "Maternal cannabis use alters ventral striatal dopamine D2 ge..." RTHC-00480. Retrieved from https://rethinkthc.com/research/dinieri-2011-maternal-cannabis-use-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.