From the article:
“What we discovered is that cocaine activates these microglia, which causes the release of an inflammatory signal which then tries to reverse the changes that cocaine is inducing in the neurons,”
[…]
The team found that TNF suppresses specific synaptic changes caused by cocaine-changes that are thought to underlie addiction. But Dr. Stellwagen explains that this beneficial mechanism doesn’t last. “The microglia response fades over time. One of the things that could transition somebody from just casual use into chronic dependency might be the fading of this adaptive signal which then allows the drugs to solidify their change to the neural circuitry.”
So can microglia be enticed to keep going? To find out, the team used a pharmaceutical agent that stimulates microglial production of TNF. Researchers observed that a cocaine-induced behavioral change in mice, the progressive increase in movement induced by cocaine,-was reduced in the animals who received this agent.
This exciting result holds promise for one day developing treatments that could cut down on drug relapse rates, which can run as high as 80 per cent.