New Tools Are Revealing How the Endocannabinoid System Works in Real Time in Living Brains | Research

The takeaway

Novel imaging and sensing technologies are revealing how endocannabinoid signals operate at specific synapses in living animals, particularly in shaping hippocampal place cell activity.

Neuroscience enthusiasts and anyone curious about how the endocannabinoid system actually works at the circuit level.

First-ever real-time tracking of endocannabinoid signaling at specific synapses in vivo

What the researchers found

New biosensors and imaging tools can now track endocannabinoid signaling at individual synapses in behaving animals. In the hippocampus, endocannabinoid-mediated inhibition by CCK-positive interneurons plays a key role in shaping place cell properties, the neurons that encode spatial location.

Why it matters

For decades, understanding of the endocannabinoid system was limited to lab-dish experiments because the signals degrade too quickly to track in living brains. These new technologies are fundamentally changing what researchers can learn about how cannabis and the natural endocannabinoid system affect brain circuits in real time.

The numbers in context

The review covers decades of research culminating in recent breakthroughs in endocannabinoid biosensors and in vivo recording methods for tracking signaling at specific synapses.

How the study worked

This is a comprehensive review synthesizing recent advances in endocannabinoid imaging, biosensors, and in vivo recording technologies. The authors focus on hippocampal circuits as a model system, examining how new tools have overcome the historical limitation that endocannabinoid lipid signals are too short-lived to study in living tissue.

What this study cannot tell us

As a review, this synthesizes existing work rather than presenting new data. Most of the highlighted advances focus on hippocampal circuits, and it remains to be seen how well the findings generalize to other brain regions.

How to read the evidence

Comprehensive review of cutting-edge neuroscience methods with strong mechanistic insights, though most findings are from animal models.

When this study was published

Published in 2025 in Neuron.

The bigger picture

Understanding endocannabinoid signaling at the synapse level in living animals could transform the fields of cannabis neuroscience and cannabinoid medicine. If researchers can see exactly which synapses are affected and when, it opens the door to much more targeted interventions.

Questions still open

How do these in vivo endocannabinoid dynamics differ between occasional and chronic cannabis users? Can these new tools help explain why cannabis affects memory and spatial navigation?

Common questions

Why was it hard to study endocannabinoids in living brains before?

Endocannabinoids are lipid molecules that break down within seconds. Previous tools could not capture such fleeting signals in intact brain tissue, limiting research to lab-dish experiments.

What are place cells and why do they matter?

Place cells are hippocampal neurons that fire when an animal is in a specific location. They are essential for spatial memory and navigation, and endocannabinoid signaling helps shape their activity.

Read the original research

Integrating endocannabinoid signaling, CCK interneurons, and hippocampal circuit dynamics in behaving animals.

Neuron, 113(12), 1862-1885

View on PubMed ↗Publisher’s paper ↗

Citation

Malhotra, Shreya; Donneger, Florian; Farrell, Jordan S; Dudok, Barna; Losonczy, Attila; Soltesz, Ivan. (2025). Integrating endocannabinoid signaling, CCK interneurons, and hippocampal circuit dynamics in behaving animals.. Neuron, 113(12), 1862-1885. https://doi.org/10.1016/j.neuron.2025.03.016