ReviewAstroglial type-1 cannabinoid receptor (CB1): A new player in the tripartite synapse

- CB1 receptors are present on brain astrocytes.
- Astroglial CB1 receptors participate in the activity of the tripartite synapse.
- Astroglial CB1 receptors mediate working memory impairments induced by cannabinoids.

The endocannabinoid system is an important regulator of physiological functions. In the brain, this control is mainly exerted through the type-1-cannabinoid (CB1) receptors. CB1 receptors are abundant at neuron terminals where their stimulation inhibits neurotransmitter release. However, CB1 receptors are also expressed in astrocytes and recent studies showed that astroglial cannabinoid signaling is a key element of the tripartite synapse. In this review we discuss the different mechanisms by which astroglial CB1 receptors control synaptic transmission and plasticity. The recent involvement of astroglial CB1 receptors in the effects of cannabinoids on memory highlights their key roles in cognitive processes and further indicates that astrocytes are central active elements of high-order brain functions.