Active endocannabinoids are secreted on extracellular membrane vesicles

Area of Science:

• Neuroscience
• Cell Biology
• Neuropharmacology

Background:

• Endocannabinoids are crucial signaling molecules in the nervous system.
• Their hydrophobic nature presents challenges for intercellular transport and membrane crossing.
• The mechanism of extracellular endocannabinoid transport remains poorly understood.

Purpose of the Study:

• To investigate the mechanism of extracellular endocannabinoid transport.
• To determine the role of microglial cells in endocannabinoid secretion.
• To elucidate the functional consequences of extracellular vesicular endocannabinoid transport.

Main Methods:

• Analysis of extracellular vesicle production by microglial cells.
• Detection of endocannabinoids on the surface of microglial extracellular vesicles.
• Electrophysiological recordings to assess the impact of microglial vesicles on neuronal activity.

Main Results:

• Microglial cells release extracellular membrane vesicles containing endocannabinoids.
• N-arachidonoylethanolamine (AEA) was identified on the surface of these vesicles.
• Microglial vesicles carrying AEA stimulated cannabinoid receptor 1 (CB1) and inhibited presynaptic transmission in GABAergic neurons.

Conclusions:

• Extracellular vesicles secreted by microglia represent a novel mechanism for endocannabinoid transport.
• This vesicular transport facilitates the functional action of endocannabinoids on neuronal targets.
• This study reveals a new pathway for endocannabinoid signaling in the central nervous system.