What topics does this cannabis study cover?

This study covers research on: Mental Health, Endocannabinoid.

Where was this research published?

Published in Psychoneuroendocrinology on June 8, 2026.

Blocking brain cannabinoid receptors in adolescence reverses stress-related social problems

Q: What did this research study find?

This study explores how blocking the **CB1R receptor** during adolescence affects stress-related social problems in female rats. Researchers exposed adolescent female rats to social instability stress (repeated isolation and unfamiliar social partners), which reduced their social interactions and mo

Adolescent cannabinoid type 1 receptor (CB1R) blockade mitigates the effects of adolescent social instability stress (SS) on socially directed behaviour in female rats.

Psychoneuroendocrinology • June 8, 2026 • Moderately Relevant

🤖

AI Summary

This study explores how blocking the CB1R receptor during adolescence affects stress-related social problems in female rats. Researchers exposed adolescent female rats to social instability stress (repeated isolation and unfamiliar social partners), which reduced their social interactions and motivation to socialize. They then tested whether blocking CB1R receptors with the drug AM251 during the same critical developmental window could reverse these stress-related deficits.

The results showed that CB1R blockade successfully restored social behavior in stressed rats, increasing both social interaction and social reward motivation—measured through how hard the animals would work to engage with social partners. Importantly, this treatment had no effect on non-stressed control rats, suggesting it specifically targeted stress-related damage rather than simply boosting sociability across the board. The study demonstrates that the adolescent endocannabinoid system plays a key role in how social stress shapes behavior during this critical developmental period.

While the researchers measured various signaling proteins related to cannabinoid, dopamine, and oxytocin systems, they found no significant changes at the molecular level, suggesting that CB1R blockade's beneficial effects may work through mechanisms beyond simple protein abundance changes. These findings highlight how the developing endocannabinoid system is vulnerable to stress disruption but can be therapeutically targeted to prevent long-term social deficits.

📄 Original Abstract

The endocannabinoid system undergoes maturation during adolescence and is involved in the development of social behaviour. In separate studies, we found: (1) that repeated cannabinoid type 1 receptor (CB1R) blockade during adolescence increased social interaction and neuronal activity in the medial prefrontal cortex and nucleus accumbens of female rats, and (2) that adolescent social instability stress (SS; daily 1-h isolation and pairing with a new cage partner from postnatal day (P) 30-45) reduced social interaction and social reward motivation in female rats. Here, we tested the possibility that adolescent CB1R blockade would mitigate the effects of SS on social behavioural deficits in female rats. The CB1R antagonist AM251 (or vehicle) was administered from P30-45 to SS or to non-stressed controls (CTL). AM251 increased social interaction and increased social reward motivation (as measured by a progressive ratio test in a social operant conditioning task) in SS female rats, with no effect in CTLs. To investigate potential molecular correlates of the increased social reward motivation in SS rats treated with AM251, we measured the abundance of signaling proteins within the endocannabinoid, dopamine, and oxytocin systems in the medial prefrontal cortex, nucleus accumbens, and medial amygdala of adult female rats. Neither SS nor AM251 treatment affected protein levels in these regions. Nevertheless, the behavioural results implicate adolescent endocannabinoid signaling as a mechanism through which adolescent social stressors shape social behaviour in female rats.

Paper Type

📄 Research

Publication

Journal: Psychoneuroendocrinology
Published: June 8, 2026
PMID: 42263537
DOI: 10.1016/j.psyneuen.2026.107937

Authors (7)

A M Leonetti Biological Sciences Department, Brock University, St. Catharines, ON, Canada.
B White Psychology Department, Brock University, St. Catharines, ON, Canada.
F F Burke Psychology Department, Brock University, St. Catharines, ON, Canada.
A C Sheehan Psychology Department, Brock University, St. Catharines, ON, Canada.
S H Murray Psychology Department, Brock University, St. Catharines, ON, Canada.
+2 more authors