THC-induced anxiety in mice involves crosstalk between cannabinoid and adenosine receptor systems in the brain

THC induced anxiety-like behavior in mice, and gene expression analysis revealed significant interaction between the cannabinoid CB1 receptor and adenosine A2A receptor systems in the hippocampus, suggesting cross-receptor modulation.

Ün, Burçin et al.·Brain and behavior·2026·Preliminary EvidenceAnimal StudyAnimal Study
RTHC-08679Animal StudyPreliminary Evidence2026RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

THC induced anxiety-like behavior in mice. Gene expression in the hippocampus showed significant interaction between cannabinoid (CB1R) and adenosine (A2AR) receptor systems. THC played a predominant role in the molecular interplay, with effects partially modulated by changes in both CB1R and A2AR expression.

Key Numbers

THC induced anxiety-like behavior. A2A agonist (CGS-21680) and antagonist (istradefylline) tested. Significant interaction between CB1R and A2AR gene expression in hippocampus. THC was the predominant factor in the molecular interplay.

How They Did This

Behavioral tests combined with molecular analyses in mice. THC effects were tested alongside the A2A receptor agonist CGS-21680 and antagonist istradefylline. Anxiety-like behavior was assessed, and hippocampal gene expression of cannabinoid and adenosine receptors was analyzed.

Why This Research Matters

Understanding why THC causes anxiety in some users is critical for developing safer cannabinoid therapeutics. The identification of adenosine A2A receptor involvement opens a new avenue for potentially blocking THC-induced anxiety without reducing therapeutic effects.

The Bigger Picture

The cannabinoid and adenosine systems interact extensively in the brain. This study adds anxiety to the list of behaviors modulated by their crosstalk, alongside motor control and cognition, potentially explaining why caffeine (an adenosine antagonist) modifies cannabis effects.

What This Study Doesn't Tell Us

Mouse study with limited translation to human anxiety. Gene expression changes do not prove functional receptor interactions. Only one THC dose tested. Male mice only.

Questions This Raises

  • ?Could adenosine A2A receptor antagonists (like caffeine) prevent THC-induced anxiety?
  • ?Does this crosstalk explain individual variability in THC anxiety responses?
  • ?Would this mechanism apply to cannabis strains with different cannabinoid profiles?

Trust & Context

Key Stat:
CB1-A2A receptor crosstalk implicated in THC anxiety
Evidence Grade:
Preliminary: single animal study combining behavioral and molecular approaches, limited to one sex and dose.
Study Age:
Published 2026.
Original Title:
Involvement of Adenosine A2A Receptors in Anxiety-Like Behaviors in Tetrahydrocannabinol-Treated Mice.
Published In:
Brain and behavior, 16(2), e71126 (2026)
Database ID:
RTHC-08679

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 does THC cause anxiety?

This study found that THC-induced anxiety involves interaction between cannabinoid CB1 receptors and adenosine A2A receptors in the hippocampus, suggesting the anxiety effect is mediated through receptor crosstalk.

Could caffeine affect THC anxiety?

The finding that adenosine A2A receptors are involved in THC anxiety is intriguing because caffeine blocks adenosine receptors, though this study did not test caffeine directly.

Read More on RethinkTHC

Cite This Study

RTHC-08679·https://rethinkthc.com/research/RTHC-08679

APA

Ün, Burçin; Akarsakarya, Zeki; Özü, Özlem Yorulmaz; Ilgaz, Nermin Seda; Yılmaz, Mehmet Bertan; Seçilmiş, Deniz; Seçilmiş, Mehmet Ata. (2026). Involvement of Adenosine A2A Receptors in Anxiety-Like Behaviors in Tetrahydrocannabinol-Treated Mice.. Brain and behavior, 16(2), e71126. https://doi.org/10.1002/brb3.71126

MLA

Ün, Burçin, et al. "Involvement of Adenosine A2A Receptors in Anxiety-Like Behaviors in Tetrahydrocannabinol-Treated Mice.." Brain and behavior, 2026. https://doi.org/10.1002/brb3.71126

RethinkTHC

RethinkTHC Research Database. "Involvement of Adenosine A2A Receptors in Anxiety-Like Behav..." RTHC-08679. Retrieved from https://rethinkthc.com/research/un-2026-involvement-of-adenosine-a2a

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.