What topics does this cannabis study cover?

This study covers research on: Endocannabinoid, Addiction, Mental Health.

Where was this research published?

Published in Neuropharmacology on August 5, 2026.

Cannabinoid signaling shapes cocaine reward differently by sex

Q: What did this research study find?

Blocking the *CB1 receptor* **reduced cocaine-evoked dopamine** in both male and female rats, with females showing greater sensitivity to this regulation.

Sex-specific differences in endocannabinoid regulation of cocaine-evoked dopamine in the medial nucleus accumbens shell.

Neuropharmacology • August 5, 2026 • Highly Relevant

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AI Summary

This preclinical study examined how endocannabinoid signaling influences cocaine-related dopamine activity in the medial shell of the nucleus accumbens, a brain region involved in reward. In male and female rats, blocking the CB1 receptor reduced cocaine-evoked dopamine, while increasing levels of the endocannabinoid 2-AG enhanced it. The abstract reports that females were more sensitive to both forms of cannabinoid-system manipulation.

Female rats also showed greater cocaine-evoked dopamine activity during the non-estrous phase than during estrous, suggesting that reproductive-cycle stage can affect this response. The findings underscore sex as an important biological variable in research on endocannabinoid regulation of drug reward. Because this was an animal study involving cocaine-related brain signaling—not a treatment trial in cannabis users—it does not show that cannabis changes cocaine use or risk in people, but it may help guide future research into sex-specific addiction biology.

💡 Key Findings

Blocking the CB1 receptor reduced cocaine-evoked dopamine in both male and female rats, with females showing greater sensitivity to this regulation.

Moderate

50%

Increasing the endocannabinoid 2-AG enhanced cocaine-evoked dopamine, and females again showed greater sensitivity.

Moderate

50%

Female rats showed greater cocaine-evoked dopamine activity during the non-estrous phase than during estrous, indicating that cycle stage influences the response.

Moderate

50%

The study concludes that sex is an important biological variable in understanding endocannabinoid regulation of drug reward.

Moderate

50%

📄 Original Abstract

Endocannabinoid (eCB) signaling is a key regulator of reward-related dopaminergic signaling, particularly in response to drugs of abuse, such as cocaine. To date, our understanding of this mechanism has primarily been limited to male subjects. Prior work establishes that female cocaine users have more adverse outcomes, and female rats show greater sensitivity to cannabinoid type 1 receptor (CB1R) regulation of cocaine self-administration. Therefore, we hypothesize that female rats exhibit enhanced eCB regulation of cocaine-evoked dopamine (DA). We used in vivo fiber photometry recording of the dopamine biosensor, dLight 1.3b, in the nucleus accumbens medial shell (NAcms) in response to cocaine in male and female rats. Rats were pretreated with cannabinoid-targeting drugs to investigate the effects of CB1R inactivation or augmentation of the eCB 2-AG on cocaine-evoked DA. Our results revealed that CB1R inactivation attenuates cocaine-evoked DA in male and female rats, but females showed enhanced sensitivity for CB1R regulation of cocaine-evoked DA. Cocaine-evoked DA was enhanced by augmenting 2-AG levels, and females again showed increased sensitivity to this manipulation. Finally, females show greater cocaine-evoked DA when in a non-estrous cycle compared to estrous, reinforcing that estrous cycle is a determinant of cocaine-evoked DA. These data indicate that females show enhanced eCB regulation of cocaine-evoked DA signaling, underscoring the importance of sex as a biological variable in our understanding of endocannabinoid regulation of drug reward.

Paper Type

📄 Research

Publication

Journal: Neuropharmacology
Published: August 5, 2026
PMID: 42556714
DOI: 10.1016/j.neuropharm.2026.111139

Authors (3)

Andrew D Gaulden Department of Pharmacology, Physiology, and Neurobiology, University of Cincinnati College of Medicine, 2120 E. Galbraith Rd, Cincinnati, OH, 45237, USA; Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA.
Kristin Chase Department of Pharmacology, Physiology, and Neurobiology, University of Cincinnati College of Medicine, 2120 E. Galbraith Rd, Cincinnati, OH, 45237, USA.
Jayme R McReynolds Department of Pharmacology, Physiology, and Neurobiology, University of Cincinnati College of Medicine, 2120 E. Galbraith Rd, Cincinnati, OH, 45237, USA; UC/UC Health Addiction Center/Research, University of Cincinnati College of Medicine, 3230 Eden Ave, Cincinnati, OH, 45267, USA. Electronic address: jayme.mcreynolds@uc.edu.