Rising stars: Modulation of brain functions by astroglial type‐1 cannabinoid receptors

The type‐1‐cannabinoid (CB 1 ) receptor is amongst the most widely expressed G protein‐coupled receptors in the brain. In few decades, CB 1 receptors have been shown to regulate a large array of functions from brain cell development and survival to complex cognitive processes. Understanding the cellular mechanisms underlying these functions of CB 1 is complex due to the heterogeneity of the brain cell types on which the receptor is expressed. Although the large majority of CB 1 receptors act on neurons, early studies pointed to a direct control of CB 1 receptors over astroglial functions including brain energy supply and neuroprotection. In line with the growing concept of the tripartite synapse highlighting astrocytes as direct players in synaptic plasticity, astroglial CB 1 receptor signaling recently emerged as the mediator of several forms of synaptic plasticity associated to important cognitive functions. Here, we shortly review the current knowledge on CB 1 receptor‐mediated astroglial functions. This functional spectrum is large and most of the mechanisms by which CB 1 receptors control astrocytes, as well as their consequences in vivo , are still unknown, requiring innovative approaches to improve this new cannabinoid research field. GLIA 2015;63:353–364