Type-2 cannabinoid receptors in neurodegeneration.

Based on its wide expression in immune cells, type-2 cannabinoid (CB2) receptors were traditionally thought to act as "peripheral receptors" with an almost exclusively immunomodulatory function. However, their recent identification in mammalian brain areas, as well as in distinct neuronal cells, has opened the way to a re-consideration of CB2 signaling in the context of brain pathophysiology, synaptic plasticity and neuroprotection. To date, accumulated evidence from several independent preclinical studies has offered new perspectives on the possible involvement of CB2 signaling in brain and spinal cord traumatic injury, as well as in the most relevant neurodegenerative disorders like Alzheimer's disease, Parkinson's disease and Huntington's chorea. Here, we will review available information on CB2 in these disease conditions, along with data that support also its therapeutic potential to treat them.