The circadian rhythm aspect of drug rewards: “Our body’s circadian rhythms affect the ‘reward’ signals we receive in the brain from drug-related behavior, and the peak time for this reward typically occurs during the evening, or dark phase. We wanted to test what the role of the brain’s immune system might have on that reward, and whether or not we could switch it off.”
Using naltrexone to block TLR4 reduces alcohol behavior:
The researchers focused their attention on the immune receptor Toll-like receptor 4 (TLR4). They administered the drug (+)-Naltrexone (pronounced: PLUS-NAL-TREX-OWN), which is known to block TLR4, to mice.
“Our studies showed a significant reduction in alcohol drinking behavior by mice that had been given (+)-Naltrexone, specifically at night time when the reward for drug-related behavior is usually at its greatest,” Mr Jacobsen says.
Interestingly and somewhat paradoxically, chronically activating TLR4 through genetic engineering-associated tricks also seems to reduce alcohol seeking in mice.