Because only a small number of genes have been solidly linked to Parkinson’s disease, researchers have been searching for environmental contaminants that might trigger the nervous system disorder. Man-made chemicals such as pesticides have been strongly associated with Parkinson’s (see page 11), but scientists are also investigating naturally occurring substances as causative agents. A research team led by Joan W. Bennett and Jason R. Richardson of Rutgers University and Gary W. Miller of Emory University reports that a chemical commonly released by fungus causes Parkinson’s-like symptoms in fruit flies (Proc. Natl. Acad. Sci. USA 2013, DOI: 10.1073/pnas.1318830110). The compound, 1-octen-3-ol, is one of the volatiles responsible for mold’s characteristic odor. When the researchers exposed fruit flies to a low (0.5 ppm) dose of the chemical, the insects’ movements slowed, similar to Parkinson’s patients. In addition, dopamine-producing nerve cells in the flies’ brains died, another hallmark of the neurodegenerative disease. The team proposes that 1-octen-3-ol interferes with dopamine transport in the brain: The survival rate of flies with a faulty transport protein in their neurons dropped after exposure to the compound. The results suggest that regular exposure to chemicals emitted by mold—a common problem in water-damaged buildings—might have neurotoxic consequences, Bennett says.