Perinatal THC exposure altered dopamine and cannabinoid gene regulation in rats, and CBD reversed the damage
Rats exposed to THC around birth showed lasting changes in dopamine D2 and cannabinoid CB1 receptor gene expression in the prefrontal cortex, along with social withdrawal and cognitive impairment, but peripubertal CBD treatment reversed these abnormalities.
Quick Facts
What This Study Found
Perinatal THC exposure increased both Cnr1 (CB1) and Drd2 (D2 receptor) mRNA levels in the adult rat prefrontal cortex, with reduced DNA methylation at the Drd2 regulatory region. These changes were accompanied by social withdrawal and cognitive impairment. Peripubertal CBD treatment reversed the behavioral abnormalities. Similar DRD2 epigenetic alterations were found in human schizophrenia patients.
Key Numbers
Increased Cnr1 and Drd2 mRNA in adult prefrontal cortex; reduced DNA methylation at Drd2 regulatory region; lower 2-AG brain levels persisting from neonatal age to adulthood; delayed neonatal reflexes; DRD2 methylation alterations confirmed in human schizophrenia patients
How They Did This
Male rats received perinatal THC exposure and were assessed at neonatal age and adulthood for molecular (gene expression, DNA methylation via pyrosequencing, endocannabinoid levels), behavioral (social interaction, cognition), and neurological (neonatal reflexes) outcomes. Some received peripubertal CBD treatment. DRD2 methylation was also measured in a human schizophrenia cohort.
Why This Research Matters
This study provides a mechanistic link between early THC exposure and schizophrenia-like changes through epigenetic modification of the dopamine system, and demonstrates that CBD may be able to reverse these alterations during a critical developmental window.
The Bigger Picture
The convergence of animal and human data on DRD2 epigenetic changes strengthens the case that early cannabinoid exposure can permanently alter dopamine system regulation, and that CBD intervention during adolescence might offer a preventive strategy.
What This Study Doesn't Tell Us
Male rats only. Perinatal exposure model (via mother) differs from typical human adolescent use. Small human schizophrenia sample for the translational component. CBD treatment timing (peripubertal) may not reflect realistic intervention windows.
Questions This Raises
- ?Could CBD treatment later in development or adulthood still reverse THC-induced epigenetic changes?
- ?Are similar DRD2 methylation patterns found in cannabis users who do not develop psychosis?
Trust & Context
- Key Stat:
- CBD reversed THC-induced social withdrawal and cognitive impairment in rats
- Evidence Grade:
- Strong mechanistic animal study with a translational human component, but limited by male-only design and small human sample.
- Study Age:
- Published in 2021.
- Original Title:
- Crosstalk between the transcriptional regulation of dopamine D2 and cannabinoid CB1 receptors in schizophrenia: Analyses in patients and in perinatal Δ9-tetrahydrocannabinol-exposed rats.
- Published In:
- Pharmacological research, 164, 105357 (2021)
- Authors:
- Di Bartolomeo, Martina(5), Stark, Tibor(2), Maurel, Oriana Maria, Iannotti, Fabio Arturo, Kuchar, Martin, Ruda-Kucerova, Jana, Piscitelli, Fabiana, Laudani, Samuele, Pekarik, Vladimir, Salomone, Salvatore, Arosio, Beatrice, Mechoulam, Raphael, Maccarrone, Mauro, Drago, Filippo, Wotjak, Carsten T, Di Marzo, Vincenzo, Vismara, Matteo, Dell'Osso, Bernardo, D'Addario, Claudio, Micale, Vincenzo
- Database ID:
- RTHC-03099
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
How did THC change gene regulation?
THC exposure around birth reduced DNA methylation at the dopamine D2 receptor gene, leading to increased D2 and CB1 receptor expression in the prefrontal cortex. These epigenetic changes persisted into adulthood and were associated with behavioral problems.
How did CBD help?
CBD treatment during the peripubertal period (roughly equivalent to early adolescence) reversed the behavioral abnormalities including social withdrawal and cognitive impairment, suggesting it modulated the altered dopaminergic activity caused by early THC exposure.
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Cite This Study
https://rethinkthc.com/research/RTHC-03099APA
Di Bartolomeo, Martina; Stark, Tibor; Maurel, Oriana Maria; Iannotti, Fabio Arturo; Kuchar, Martin; Ruda-Kucerova, Jana; Piscitelli, Fabiana; Laudani, Samuele; Pekarik, Vladimir; Salomone, Salvatore; Arosio, Beatrice; Mechoulam, Raphael; Maccarrone, Mauro; Drago, Filippo; Wotjak, Carsten T; Di Marzo, Vincenzo; Vismara, Matteo; Dell'Osso, Bernardo; D'Addario, Claudio; Micale, Vincenzo. (2021). Crosstalk between the transcriptional regulation of dopamine D2 and cannabinoid CB1 receptors in schizophrenia: Analyses in patients and in perinatal Δ9-tetrahydrocannabinol-exposed rats.. Pharmacological research, 164, 105357. https://doi.org/10.1016/j.phrs.2020.105357
MLA
Di Bartolomeo, Martina, et al. "Crosstalk between the transcriptional regulation of dopamine D2 and cannabinoid CB1 receptors in schizophrenia: Analyses in patients and in perinatal Δ9-tetrahydrocannabinol-exposed rats.." Pharmacological research, 2021. https://doi.org/10.1016/j.phrs.2020.105357
RethinkTHC
RethinkTHC Research Database. "Crosstalk between the transcriptional regulation of dopamine..." RTHC-03099. Retrieved from https://rethinkthc.com/research/di-2021-crosstalk-between-the-transcriptional
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.