Cannabinoid Ligand‐Mediated Glycogen Depletion in Astrocytes Is Associated With Increased Intracellular Calcium, Energy Metabolism, and Membrane Dynamics

ABSTRACT Astrocytes orchestrate brain energy metabolism and respond to endocannabinoids via cannabinoid receptor type 1 (CB1R), whereas the contribution of CB2R remains uncertain. We combined live‐cell Förster resonance energy transfer sensors for D‐glucose and L‐lactate, intracellular Ca 2+ imaging, glycogen assays, and whole‐cell patch‐clamp capacitance measurements to define how cannabinoid ligands shape astrocyte physiology in primary rat cultures. The CB1‐selective agonist ACEA triggered rapid, transient elevations in [Ca 2+ ]ᵢ and metabolic readouts, whereas the CB2‐biased ligands AM1241 and Gp1a produced sustained metabolic effects, including prolonged increases in intracellular D‐glucose and L‐lactate. AM1241 additionally evoked glycogen depletion. Ligand applications also increased membrane capacitance, consistent with enhanced exocytotic activity and altered membrane dynamics. CB1 immunoreactivity predominated over a weak CB2‐like signal, and RT‐qPCR detected Cnr1 but not Cnr2 transcripts under our conditions. Accordingly, we interpret AM1241/Gp1a actions as ligand‐evoked effects that are predominantly CB1‐linked (and/or off‐target at the concentrations used). Together, these results show that cannabinoid ligands robustly remodel astrocytic energy metabolism and membrane behavior chiefly through CB1‐associated pathways, highlighting a functional axis between cannabinoid signaling, Ca 2+ mobilization, glycogen remodeling, and exocytosis in astrocytes. image