Huntington’s disease and other neurodegenerative illnesses are thought to progress via the production, aggregation, and cell-to-cell spread of misfolded proteins. The mechanism of the spread, however, remains unclear.

Researchers examined the spread of pathogenic aggregates in a Drosophila model of Huntington’s disease. Drosophila has been used to model a number of neurodegenerative diseases.

The authors fluorescently labeled a mutant version of the human huntingtin (Htt) protein and visualized the spread of Htt aggregates in the Drosophila brain.

When mutant Htt is expressed in olfactory receptor neurons, the authors report, aggregates of Htt accumulate at synaptic terminals—bulbs at the ends of neurons that store neurotransmitters and coordinate their release—and spread from the antennal lobe to other areas of the brain.

The spread contributes to the deterioration of vulnerable neurons, a process that can be prevented by blocking the release of Htt aggregates or their uptake by other neurons.

According to the authors, clear understanding of aggregate development and spread could aid in the discovery of genetic or pharmacological interventions for neurodegenerative illnesses.