“More evidence suggests that dorsal spinal cord microglia is an important site contributing to CB2 receptor-mediated analgesia. The upregulation of P2Y12 and P2Y13 purinoceptors in spinal dorsal horn microglia is involved in the development of pain behavior caused by peripheral nerve injury. However, it is not known whether the expression of P2Y12 and P2Y13 receptors at spinal dorsal horn will be influenced after CB2 receptor activation in neuropathic pain rats. Chronic constriction injury (CCI) and intrathecal ADPbetaS injection were performed in rats to induce neuropathic pain.
In CCI- and ADPbetaS-treated rats, AM1241 pretreatment could efficiently activate CB2 receptor, while inhibiting p38MAPK and NF-kappaB activation in the dorsal spinal cord. CB2 receptor stimulation decreased P2Y13 receptor expression via p38MAPK/NF-kappaB signaling. On the other hand, CB2 receptor activation decreased P2Y12 receptor expression via p38MAPK-independent NF-kappaB signaling pathway.”
https://www.ncbi.nlm.nih.gov/pubmed/28899427
“Morphine is widely used as an analgesic to treat moderate to severe pain, but chronic morphine use is associated with development of tolerance and dependence, which limits its analgesic efficacy. Our previous research has showed that nonanalgetic dose of a 
“Let’s get medicinal, says Olivia Newton-John, who has spoken out about the use of medicinal cannabis on a recent visit to Australia. “I will do what I can to encourage it. It’s an important part of treatment and it should be available,” the singer, who announced a second battle with breast cancer in May, told News Corp Australia. The Australian entertainer said the drug – which is legal in her home state of California – had helped her during her second fight against cancer.”