According to a new study published in Psychopharmacology, cannabidiol (CBD), the major non-psychoactive compound found in cannabis, can enhance a specific type of social memory in mice. This effect appears to be linked to changes in acetylcholine signaling within a key brain region known as the basal forebrain. The findings offer new insights into how CBD may influence cognitive processes and social behavior in humans.

Cannabidiol (commonly known as CBD) has gained widespread attention for its potential therapeutic effects on anxiety and cognition. However, the exact brain mechanisms underlying these effects remain unclear.

In this study, researchers investigated whether CBD could enhance social learning in mice by modulating a brain chemical called acetylcholine, which plays a key role in memory and attention.

The focus of the research was a behavior known as "social transmission of food preference" (STFP). This learning method allows mice to acquire information about safe food choices through interaction with other mice that have recently eaten a particular flavor of food. It relies on memory and social interaction and serves as a model for studying cognitive processes involved in social learning.

The researchers conducted a series of experiments using male C57BL/6J mice, a commonly used strain in laboratory research. Thirty minutes before the observer mice interacted socially with a demonstrator mouse that had consumed a specific flavored food, the researchers administered a single dose of CBD (20 mg/kg) to the observer mice. After the interaction, the observer mice were tested to determine whether they would preferentially consume the same flavored food, indicating that they had learned and remembered the social cue.

They found that mice treated with CBD showed a significantly stronger preference for the food flavor demonstrated by the other mouse, compared to untreated controls. This enhanced preference was observed immediately after the social interaction and persisted 24 hours later, suggesting that CBD improved both short-term and long-term memory of the social information.

To understand how CBD produced this effect, the researchers focused on the role of acetylcholine—a neurotransmitter critical for learning and memory. Acetylcholine is produced in the basal forebrain and acts on receptors throughout the brain, including in the hippocampus and prefrontal cortex.

In one experiment, the researchers reduced the activity of an enzyme called acetylcholinesterase, which breaks down acetylcholine in the brain. They did this by directly injecting an antisense oligonucleotide into the basal forebrain to lower acetylcholinesterase levels. This intervention also enhanced food preference memory in the mice, mimicking the effects of CBD.

In another experiment, the mice were given a drug called scopolamine, which blocks muscarinic acetylcholine receptors. When CBD and scopolamine were administered together, the memory-enhancing effect of CBD disappeared. This indicates that muscarinic acetylcholine receptors are crucial for CBD’s cognitive benefits.

To further explore the relationship between CBD and acetylcholine, the researchers measured acetylcholine levels in the basal forebrain after CBD administration. Interestingly, while overall acetylcholine levels did not increase across all CBD-treated mice, those mice that showed stronger food preference memory also had higher acetylcholine levels in this brain region. This correlation was not observed in mice that did not receive CBD.

These results suggest that CBD enhances social learning and memory by increasing acetylcholine signaling in responder mice. Specifically, activation of muscarinic receptors in the basal forebrain appears to be necessary for this cognitive effect.

Importantly, the researchers ruled out several alternative explanations for their findings. CBD did not affect the mice’s overall food intake, locomotor activity, or basic social behaviors. It also did not impair or enhance the mice's ability to detect or discriminate odors, which are key to the STFP task. While CBD did reduce anxiety-like behavior shortly after administration, this effect had dissipated by the time of the 24-hour memory test—indicating that anxiety reduction alone does not explain the observed memory enhancement.

The study also highlights individual differences in response to CBD among animals—not all CBD-treated mice showed increased acetylcholine levels or improved memory. Only a subset appeared to benefit, which the researchers suggest may have implications for personalized medicine. In clinical settings, CBD may enhance cognitive function in some individuals but have limited or no effects in others.

These findings also support a broader role for the brain's cholinergic system in social learning. Previous research has shown that acetylcholine is essential for learning from others, and damage to cholinergic neurons in the basal forebrain can impair social memory. This study expands on that work by showing that pharmacologically increasing acetylcholine activity—either by inhibiting its breakdown or through CBD treatment—can enhance social memory.

Of course, the study has some limitations. The experiments were conducted in healthy, young male mice, so it's unclear whether the same effects would be seen in female mice, older animals, or those with cognitive impairments.

The researchers also used only a single dose of CBD, without exploring whether lower or higher doses might yield different effects. Finally, while the study suggests that muscarinic receptors are involved, it does not identify which specific receptor subtypes are responsible for the observed changes.

Future research could explore in more detail how CBD affects cholinergic signaling—whether it acts directly on acetylcholine receptors or indirectly by altering enzyme activity. It will also be important to test whether these effects can be replicated in animal models of cognitive impairment or in humans.