A new study shows inhaling toluene, a compound commonly found in products like paint thinner and glue, triggers the release of dopamine in the brain of laboratory rats.
Dopamine release is associated with a feeling of euphoria and is linked to drug addiction.
Although many young people may view huffing as a harmless party drug, the researchers say their results suggest toluene activates the brain in the same way illegal drugs like cocaine do and that inhalant abuse may lead to drug addiction.
Inhaling toluene can also cause brain damage and sudden death.
Huffing Hits Brain Hard
In the study, published in Neuropsychopharmacology, researchers applied concentrations of toluene similar to those found in humans after "huffing" to the brains of rats, then measured the response.
They found the drug was quickly absorbed by brain tissue and directly activated the release of dopamine (DA) in the brain.
In addition, the magnitude of the release did not decrease with prolonged exposure to toluene.
The researchers say the study shows the effects of inhalant abuse on the brain may be more serious than previously thought.
Earlier conclusions that the huffer's high is caused by something other than dopamine release "may be premature," write researcher Arthur C. Riegel, of the department of pharmacology at the University of Arizona, Tucson, and Oregon Health & Science University, Portland, and colleagues.
"Furthermore, given the alarming increase in inhalant abuse among youth, additional studies examining the interaction of toluene and other inhalants with the [dopamine reward] pathway are warranted," they write.