Activating CB2 Receptors While Blocking Dopamine D4 Reduced Binge Eating More Than Either Alone in Mice | Research

The takeaway

Combining a CB2 receptor activator with a dopamine D4 blocker produced a stronger reduction in binge-like eating of palatable food than the dopamine blocker alone.

Researchers interested in the endocannabinoid system's role in appetite regulation and eating disorders.

CB2 activation enhanced dopamine-based binge eating reduction

What the researchers found

In mice given 1-hour access to palatable food, a dopamine D4 receptor antagonist (L-745870) reduced binge-like intake. Adding a CB2 receptor agonist (HU308) to the D4 antagonist produced an even greater reduction. The CB2 antagonist (AM630) combined with the D4 antagonist did not enhance the effect, suggesting the additional benefit came specifically from CB2 activation.

Why it matters

Binge eating disorder involves dysregulation of the brain's reward system. This study reveals a previously unknown interaction between the cannabinoid and dopamine systems in controlling binge-like behavior, suggesting that targeting both systems simultaneously could be more effective than targeting either alone.

The numbers in context

34 mice total. 12 baseline binge sessions + 3 treatment sessions. Four treatment groups tested. D4 antagonist (L-745870) reduced binge intake; adding CB2 agonist (HU308) produced even greater reduction.

How the study worked

34 adult male C57BL6/J mice housed individually with ad libitum standard diet. Binge eating was modeled by providing 1-hour access to palatable food across 12 baseline sessions. Mice were then randomly assigned to four treatment groups (vehicle, D4 antagonist alone, D4 antagonist + CB2 agonist, D4 antagonist + CB2 antagonist) for three additional sessions.

What this study cannot tell us

Animal study in male mice only; no female mice tested. Small sample size per group. Short treatment period (3 sessions). Palatable food binge model may not fully capture human binge eating disorder. Only intraperitoneal drug administration tested.

How to read the evidence

Preliminary: animal study with novel finding, but small sample size and male-only design.

When this study was published

Published in 2025.

The bigger picture

The endocannabinoid system's role in appetite and reward is well established through CB1 receptors, but CB2's involvement in eating behavior is a newer finding. This study adds to growing evidence that CB2 receptors in dopamine neurons help modulate reward-driven behaviors beyond just drug seeking.

Questions still open

Would CB2 activation reduce binge eating in females?
Does this dopamine-cannabinoid interaction apply to other reward-driven behaviors?
Could targeting CB2 receptors help treat binge eating disorder in humans?

Common questions

Does the endocannabinoid system affect binge eating?

This mouse study suggests CB2 cannabinoid receptors interact with dopamine D4 receptors to modulate binge-like eating behavior. Activating CB2 while blocking D4 reduced binge eating more than blocking D4 alone.

Could cannabinoid-based treatments help with binge eating disorder?

This early animal research suggests CB2 receptor activation may help reduce binge-like eating by modulating reward pathways. Human studies would be needed to explore this potential.

Read the original research

Coadministration antagonist dopamine receptor D4 with CB2 receptor agonist decreases binge-like intake of palatable food in mice.

Frontiers in behavioral neuroscience, 19, 1572374

View on PubMed ↗Publisher’s paper ↗

Citation

Rodríguez-Serrano, Luis Miguel; López-Castillo, Ana Paola; Cabrera-Mejía, María Cristina; Cedillo-Figueroa, Ana Sofía; Zepeda-Ortigosa, Nyahn; Carregha-Lozano, Carolina; Chávez-Hernández, María Elena. (2025). Coadministration antagonist dopamine receptor D4 with CB2 receptor agonist decreases binge-like intake of palatable food in mice.. Frontiers in behavioral neuroscience, 19, 1572374. https://doi.org/10.3389/fnbeh.2025.1572374