Ultrastructural and physiologycal studies on cannabinoid CB1 receptors localized in astroglia
Laboratory of Ultrastructural and Functional Neuroanatomy of the Synapse, ACHUCARRO
strocytes communicate bi-directionally with neurons. The cannabinoid CB1 receptor is known to be localized to astrocytes and astroglial mitochondria where its functional role has been demonstrated. In this background, I will discuss in my talk my recent results showing that a higher amount of CB1 receptors can be revealed in astrocytes using antibodies against the glutamate aspartate transporter (GLAST), instead of the commonly used glial fibrillary acidic protein (GFAP) as astroglial marker.
I will also discuss that low frequency stimulation of excitatory pathways in the hippocampus and prefrontal cortex of 14-week-old mice triggers CB1 receptor-dependent long-term potentiation (CB1-LTP) in contrast to the usual long term depression (CB1-LTD), suggesting that excitatory synaptic plasticity driven by CB1 receptors shifts with age. Interestingly, this shift was independent of CB1 receptors in astrocytes as the lack of CB1 receptors in these glial cells did not affect CB1-LTP.