Spinal MCP-1 Contributes to the Development of Morphine Antinociceptive Tolerance in Rats

This study revealed for the first time that spinal neuronal MCP-1 is a key mediator of the spinal microglial activation and that spinal MCP-1 is involved in morphine antinociceptive tolerance. Inhibition of MCP-1 may provide a new therapy for morphine tolerance management.