RT Journal Article
SR Electronic
T1 A fluorescent sensor for spatiotemporally resolved endocannabinoid dynamics <em>in vitro</em> and <em>in vivo</em>
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.10.08.329169
DO 10.1101/2020.10.08.329169
A1 Ao Dong
A1 Kaikai He
A1 Barna Dudok
A1 Jordan S Farrell
A1 Wuqiang Guan
A1 Daniel J Liput
A1 Henry L Puhl
A1 Ruyi Cai
A1 Jiali Duan
A1 Eddy Albarran
A1 Jun Ding
A1 David M Lovinger
A1 Bo Li
A1 Ivan Soltesz
A1 Yulong Li
YR 2020
UL http://biorxiv.org/content/early/2020/10/20/2020.10.08.329169.abstract
AB Endocannabinoids (eCBs) are retrograde neuromodulators that play an important role in a wide range of physiological processes; however, the release and in vivo dynamics of eCBs remain largely unknown, due in part to a lack of suitable probes capable of detecting eCBs with sufficient spatiotemporal resolution. Here, we developed a new eCB sensor called GRABeCB2.0. This genetically encoded sensor consists of the human CB1 cannabinoid receptor fused to circular-permutated EGFP, providing cell membrane trafficking, second-resolution kinetics, high specificity for eCBs, and a robust fluorescence response at physiological eCB concentrations. Using the GRABeCB2.0 sensor, we monitored evoked changes in eCB dynamics in both cultured neurons and acute brain slices. Interestingly, in cultured neurons we also observed spontaneous compartmental eCB transients that spanned a distance of approximately 11 μm, suggesting constrained, localized eCB signaling. Moreover, by expressing GRABeCB2.0 in the mouse brain, we readily observed foot shock-elicited and running-triggered eCB transients in the basolateral amygdala and hippocampus, respectively. Lastly, we used GRABeCB2.0 in a mouse seizure model and observed a spreading wave of eCB release that followed a Ca2+ wave through the hippocampus. Thus, GRABeCB2.0 is a robust new probe for measuring the dynamics of eCB release under both physiological and pathological conditions.Competing Interest StatementY. L. has filed patent applications, the value of which might be affected by this publication.