Adolescent cannabis vapor exposure produced opposite brain changes in male and female mice on MRI
Chronic inhaled cannabis vapor during adolescence produced sexually dimorphic brain changes in mice: females showed altered grey matter structure in forebrain and hindbrain, while males showed disrupted functional connectivity in hippocampal circuits and cognitive deficits.
Quick Facts
What This Study Found
Female mice showed altered fractional anisotropy and apparent diffusion coefficient (measures of brain microstructure) in forebrain and hindbrain. Males showed increased functional coupling with thalamus, hypothalamus, and brainstem reticular activating system, altered hippocampal connectivity, and deficits in novel object recognition. The effects were sexually dimorphic with minimal overlap.
Key Numbers
Daily exposure from postnatal day 23-51; 10.3% THC cannabis; 139 brain areas analyzed via 3D atlas; males showed cognitive deficits on novel object recognition.
How They Did This
Female and male mice were exposed daily to vaporized cannabis (10.3% THC, 0.05% CBD) or placebo from postnatal day 23-51 (periadolescence). After cessation, multimodal MRI (voxel-based morphometry, diffusion-weighted imaging, resting-state functional connectivity) was performed using a 3D atlas with 139 brain regions. Novel object preference tested.
Why This Research Matters
This is one of the first studies to use clinically relevant inhaled cannabis vapor (rather than injected THC) with multimodal brain imaging in adolescent animals, providing data more translatable to human adolescent cannabis use.
The Bigger Picture
The finding that adolescent cannabis affects male and female brains in completely different ways has implications for sex-specific risk assessment and challenges the one-size-fits-all approach to cannabis education.
What This Study Doesn't Tell Us
Mouse model may not fully translate to humans. Single cannabis concentration tested. Only one cognitive test used. No dose-response or duration comparisons. Short-term follow-up after cessation.
Questions This Raises
- ?Do these sex differences persist into adulthood or resolve?
- ?Would lower THC concentrations produce similar effects?
- ?Are the female structural changes or male functional changes more clinically relevant?
Trust & Context
- Key Stat:
- Opposite brain changes: structural in females, functional in males
- Evidence Grade:
- Rigorous multimodal MRI study with clinically relevant inhaled cannabis, but animal model with single concentration.
- Study Age:
- Published in 2022.
- Original Title:
- Changes in brain structure and function following chronic exposure to inhaled vaporised cannabis during periadolescence in female and male mice: A multimodal MRI study.
- Published In:
- Addiction biology, 27(3), e13169 (2022)
- Authors:
- Coleman, James R(2), Madularu, Dan(2), Ortiz, Richard J, Athanassiou, Maria, Knudsen, Alexa, Alkislar, Ilayda, Cai, Xuezhu, Kulkarni, Praveen P, Cushing, Bruce S, Ferris, Craig F
- Database ID:
- RTHC-03765
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Does cannabis affect male and female brains differently?
In this mouse study, yes. Adolescent cannabis exposure changed brain structure in females (grey matter microarchitecture in forebrain and hindbrain) but altered brain connectivity in males (hippocampal circuits and brainstem coupling), with males also showing cognitive deficits.
Why is this study more relevant than older animal research?
This study used inhaled vaporized cannabis rather than injected THC, better mimicking how humans actually consume cannabis. It also used multimodal MRI to examine both brain structure and function across 139 brain regions.
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Cite This Study
https://rethinkthc.com/research/RTHC-03765APA
Coleman, James R; Madularu, Dan; Ortiz, Richard J; Athanassiou, Maria; Knudsen, Alexa; Alkislar, Ilayda; Cai, Xuezhu; Kulkarni, Praveen P; Cushing, Bruce S; Ferris, Craig F. (2022). Changes in brain structure and function following chronic exposure to inhaled vaporised cannabis during periadolescence in female and male mice: A multimodal MRI study.. Addiction biology, 27(3), e13169. https://doi.org/10.1111/adb.13169
MLA
Coleman, James R, et al. "Changes in brain structure and function following chronic exposure to inhaled vaporised cannabis during periadolescence in female and male mice: A multimodal MRI study.." Addiction biology, 2022. https://doi.org/10.1111/adb.13169
RethinkTHC
RethinkTHC Research Database. "Changes in brain structure and function following chronic ex..." RTHC-03765. Retrieved from https://rethinkthc.com/research/coleman-2022-changes-in-brain-structure
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.