Botox's pathway to neuron paralysis discovered

Scientists at the University of Queensland in Australia have discovered that botulinum neurotoxin, the highly toxic substance used in Botox, uses three receptors to enter neurons. Previous research had indicated that only two receptors were necessary for the toxin's entry into cells. By using a technique called single-molecule imaging, the researchers were able to track the movement of molecules labelled with fluorescent dye. They placed the toxin into a dish with neurons from rats and trained one camera on the neurotoxin and another on receptors in the neuron membranes, also marked with different-coloured dyes. The researchers found that all three receptors are needed for botulinum neurotoxin type A to infiltrate cells. Future drugs that block the three receptors from binding together could stop the toxin from infecting neurons. The discovery could aid efforts to develop an antidote to Botox's neurotoxic effects, which can result in paralysis or even death. In small, therapeutic doses, Botox can ease muscle spasms, treat migraines, or reduce wrinkles. However, at high doses, the molecule causes botulism, a potentially fatal disease with few treatments. By understanding more about the mechanism of cell entry, scientists are one step closer to preventing cell entry and preventing botulism.