Cannabinoid type 1 receptors (CB1Rs) are functionally active within the laterodorsal tegmental nucleus (LDT), which is critically involved in control of rapid eye movement sleep, cortical arousal, and motivated states. To further characterize the cellular consequences of activation of CB1Rs in this nucleus, we examined whether CB1R activation led to rises in intracellular Ca2? ([Ca2?]i) and whether processes shown in other regions to involve endocannabinoid (eCB) transmission were present in the LDT. Using a combination of Ca2? imaging in multiple cells loaded with Ca2? imaging dye via ‘bulk-loading’ or in single cells loaded with dye via a patch-clamp electrode, we found that WIN 55212-2...
