Selective GRAB sensors reveal distinct endocannabinoid dynamics in vivo
Ru-Yi Cai, Yue-Qi Yang, Shang-Xuan Cai, Ana Silva de Sousa, Kathryn L. Todd, Lei Wang, Weijian Teo, Ao Dong, Shuaiyu Chen, Hui Dong, Huan Wang, Zhao-Fa Wu, Yanling Qiao, Peng Xu, Chen Song, Stephanie J. Cragg, Yu-Long Li
bioRxiv August 12, 2026 preprint DOI: 10.64898/2026.08.06.743280 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Preclinical experimental study |
|---|---|
| Population | Cultured neurons, acute brain slices, and freely behaving mice |
| Interventions | GRAB2-AG2.0 GRABAEA2.0 Δ9-THC |
| Measures | GRAB2-AG2.0, GRABAEA2.0 |
| Key findings | The new sensors GRAB2-AG2.0 and GRABAEA2.0 selectively detect 2-AG and anandamide, respectively, and revealed distinct dynamics in mice: aversive stimulation preferentially evoked 2-AG, and Δ9-THC elicited a sustained 2-AG signal in the nucleus accumbens shell that was reduced, along with Δ9-THC-induced hypolocomotion, by local Dagla deletion. The authors propose an endogenous 2-AG component in the behavioral response to Δ9-THC. |
Abstract
The endocannabinoid system modulates diverse physiological processes via two endogenous lipid ligands, 2-arachidonoylglycerol (2-AG) and anandamide (AEA); however, their specific spatiotemporal dynamics remain poorly understood owing to the lack of selective probes. Here, we developed GRAB2-AG2.0 and GRABAEA2.0, two genetically encoded fluorescent sensors that selectively detect 2-AG and AEA, respectively. Both sensors exhibited high apparent affinity and molecular specificity for their respective ligands, enabling the real-time detection of 2-AG and AEA release evoked by electrical stimulation in cultured neurons and acute brain slices. In freely behaving mice, these sensors revealed ligand- and context-specific eCB dynamics: aversive stimulation preferentially evoked 2-AG, whereas psychoactive drugs produced distinct 2-AG and AEA responses. Notably, Δ9-THC elicited a sustained 2-AG signal in the nucleus accumbens shell, and local deletion of Dagla markedly attenuated both this signal and Δ9-THC-induced hypolocomotion. These sensors therefore enable detecting 2-AG and AEA signaling seperately and reveal an endogenous 2-AG component of the behavioral response to Δ9-THC.