Inhaled cannabis vapor lowered heart rate and blood pressure but increased anxiety-like behavior in mice
Mice exposed to vaporized cannabis (10.3% THC) via nose-only inhalation showed decreased heart rate and blood pressure, anxiety-like behavior, and altered brain activation patterns related to sensory awareness.
Quick Facts
What This Study Found
Cannabis inhalation decreased heart rate and blood pressure but promoted anxiety-like behavior in the open field test. Brain imaging (BOLD fMRI) showed cannabis increased sensory awareness while reducing behavioral arousal. Blood THC levels peaked at 136 ng/mL and increased linearly with dose.
Key Numbers
Cannabis contained 10.3% THC, 0.05% CBD. Particle size: 243 nm (count median diameter). Peak blood THC: 136 ng/mL. THC levels increased linearly with aerosolized mass.
How They Did This
Male adult C57BL/6 mice received nose-only exposure to vaporized cannabis (10.3% THC, 0.05% CBD). Researchers measured serum THC levels, blood pressure, heart rate, open-field behavior, and awake brain activity via BOLD fMRI.
Why This Research Matters
This study establishes a controlled mouse model for cannabis inhalation that mimics human delivery, enabling future research on chronic cannabis use effects that would be difficult to study in humans.
The Bigger Picture
The combination of cardiovascular depression and anxiety-like behavior mirrors some acute effects reported by human cannabis users, validating this animal model for future research on chronic inhalation effects.
What This Study Doesn't Tell Us
Animal study using a single acute exposure in male mice only. The nose-only delivery system, while controlled, may not perfectly replicate human smoking or vaping behavior. Only one cannabis formulation was tested.
Questions This Raises
- ?Would chronic exposure produce different cardiovascular and behavioral outcomes?
- ?How would results differ with balanced THC/CBD formulations?
- ?Would female mice show different responses?
Trust & Context
- Key Stat:
- Peak blood THC: 136 ng/mL; heart rate and blood pressure decreased
- Evidence Grade:
- Preliminary: single acute-exposure animal study establishing a new methodology.
- Study Age:
- Published in 2020 in Inhalation Toxicology.
- Original Title:
- Acute neuroradiological, behavioral, and physiological effects of nose-only exposure to vaporized cannabis in C57BL/6 mice.
- Published In:
- Inhalation toxicology, 32(5), 200-217 (2020)
- Authors:
- Farra, Yasmeen M, Eden, Matthew J, Coleman, James R(2), Kulkarni, Praveen, Ferris, Craig F, Oakes, Jessica M, Bellini, Chiara
- Database ID:
- RTHC-02547
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Why use nose-only exposure instead of a smoking chamber?
Nose-only exposure provides more precise control over the dose each mouse receives and better mimics how smoke or vapor reaches human airways, compared to whole-body chambers where mice also absorb compounds through skin and fur.
What did the brain imaging show?
BOLD fMRI revealed that cannabis increased brain activity in areas related to sensory processing while decreasing activity in regions associated with behavioral arousal, a pattern consistent with heightened sensory awareness and reduced motor activity.
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Cite This Study
https://rethinkthc.com/research/RTHC-02547APA
Farra, Yasmeen M; Eden, Matthew J; Coleman, James R; Kulkarni, Praveen; Ferris, Craig F; Oakes, Jessica M; Bellini, Chiara. (2020). Acute neuroradiological, behavioral, and physiological effects of nose-only exposure to vaporized cannabis in C57BL/6 mice.. Inhalation toxicology, 32(5), 200-217. https://doi.org/10.1080/08958378.2020.1767237
MLA
Farra, Yasmeen M, et al. "Acute neuroradiological, behavioral, and physiological effects of nose-only exposure to vaporized cannabis in C57BL/6 mice.." Inhalation toxicology, 2020. https://doi.org/10.1080/08958378.2020.1767237
RethinkTHC
RethinkTHC Research Database. "Acute neuroradiological, behavioral, and physiological effec..." RTHC-02547. Retrieved from https://rethinkthc.com/research/farra-2020-acute-neuroradiological-behavioral-and
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.