From Science:
Sniffing, or huffing, glue, paint, cleaning fluids, and nail polish remover may appear relatively harmless, but it is physiologically no different from other forms of drug abuse. That’s the conclusion of a new study that shows that toluene, the solvent in many of these inhaled substances, has the same effect on our brains as notorious drugs like cocaine and methamphetamine. The findings explain a long-standing mystery about the impact of this addictive substance on the brain and suggest ways of developing treatments for addiction.
Solvent abuse increases a person’s desire for other drugs, boosts the risk of depression and suicide, and irreversibly damages the brain, heart, kidney, and liver. But the exact effect of solvents such as toluene on our brains has remained unclear. Unlike other drugs that target specific areas of the brain, solvents were thought to act on all brain regions. Then, in 2002, neurologist Stephen Dewey of Brookhaven National Laboratory, in Upton, New York, and colleagues showed that toluene homes in on brain areas such as the reward center, which includes two main structures, the ventral tegmental area (VTA,) and the nucleus accumbens (ACB). Drugs such as nicotine and cocaine activate a group of dopamine-producing neurons in the VTA. These neurons start firing and release dopamine–the brain’s feel-good chemical–into the VTA and the ACB.
More here.