Synthetic cannabinoids worsened alcohol-related motor impairment in mice by reducing brain glutamate

In mice, combining synthetic cannabinoids (JWH-018 or AB-CHMINACA) with alcohol produced greater motor impairment than either substance alone, through a mechanism involving reduced glutamate signaling in the cerebellum.

Funada, Masahiko et al.·Toxicology and applied pharmacology·2020·Preliminary EvidenceAnimal StudyAnimal Study
RTHC-02560Animal StudyPreliminary Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

Synthetic cannabinoids enhanced ethanol-induced motor impairment on a rotarod test. This effect was blocked by a CB1 receptor antagonist but not a CB2 antagonist. The combination reduced extracellular glutamate levels in the cerebellum more than alcohol alone.

Key Numbers

Ethanol dose: 2 g/kg. Two synthetic cannabinoids tested: JWH-018 and AB-CHMINACA. Effects blocked by CB1 antagonist AM251 but not CB2 antagonist AM630.

How They Did This

Mouse study testing motor coordination on an accelerating rotarod after administering ethanol (2 g/kg) alone or combined with JWH-018 or AB-CHMINACA. Microdialysis measured cerebellar glutamate levels. Microelectrode arrays assessed neuronal network activity in cerebellar cultures.

Why This Research Matters

Synthetic cannabinoids and alcohol are frequently used together, and this study identifies a specific brain mechanism (reduced cerebellar glutamate) that explains why the combination causes worse motor impairment than either substance alone.

The Bigger Picture

The finding has direct relevance to driving safety and injury risk, as many synthetic cannabinoid users also drink alcohol, and the combination produces motor impairments greater than either substance alone.

What This Study Doesn't Tell Us

Animal study using injected synthetic cannabinoids, which may not replicate human exposure patterns. Only two synthetic cannabinoids were tested among hundreds that exist. The specific glutamate mechanism may not fully explain real-world impairment.

Questions This Raises

  • ?Do natural cannabis and alcohol show the same synergistic motor impairment mechanism?
  • ?Could this cerebellar glutamate pathway be a target for reducing combined impairment?

Trust & Context

Key Stat:
Synthetic cannabinoids + alcohol = greater motor impairment via CB1
Evidence Grade:
Preliminary: animal study establishing mechanism, not yet confirmed in humans.
Study Age:
Published in 2020 in Toxicology and Applied Pharmacology.
Original Title:
Synthetic cannabinoids enhanced ethanol-induced motor impairments through reduction of central glutamate neurotransmission.
Published In:
Toxicology and applied pharmacology, 408, 115283 (2020)
Database ID:
RTHC-02560

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

Why is this combination dangerous?

Both synthetic cannabinoids and alcohol impair motor coordination individually. This study shows the combination has a synergistic effect, reducing cerebellar glutamate more than either substance alone, leading to even worse motor impairment.

Does natural cannabis interact with alcohol the same way?

This study only tested synthetic cannabinoids. While natural THC and alcohol are also known to impair motor function together, the specific mechanism may differ because synthetic cannabinoids often have higher potency at CB1 receptors.

Read More on RethinkTHC

Cite This Study

RTHC-02560·https://rethinkthc.com/research/RTHC-02560

APA

Funada, Masahiko; Takebayashi-Ohsawa, Mika; Tomiyama, Ken-Ich. (2020). Synthetic cannabinoids enhanced ethanol-induced motor impairments through reduction of central glutamate neurotransmission.. Toxicology and applied pharmacology, 408, 115283. https://doi.org/10.1016/j.taap.2020.115283

MLA

Funada, Masahiko, et al. "Synthetic cannabinoids enhanced ethanol-induced motor impairments through reduction of central glutamate neurotransmission.." Toxicology and applied pharmacology, 2020. https://doi.org/10.1016/j.taap.2020.115283

RethinkTHC

RethinkTHC Research Database. "Synthetic cannabinoids enhanced ethanol-induced motor impair..." RTHC-02560. Retrieved from https://rethinkthc.com/research/funada-2020-synthetic-cannabinoids-enhanced-ethanolinduced

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.