It was a pleasure to read this work from the Masliah/Lee duo on the cell-to-cell transmission of α-synuclein (Desplats et al., 2009). This work shows that α-synuclein can be released from cells and is taken up by the neighboring cell, thereby aiding in a progressive spread of the protein. This work continues Seung-Jae Lee’s previous work showing that α-synuclein could be released (Lee et al., 2005
) and taken up in neurons (Lee et al., 2008
; Lee et al., 2008
). While the exact mechanism of the release is currently not well defined, this group has done elegant cell biology work to study the internalization mechanism. They show that fluorescently labeled, recombinant α-synuclein is internalized from the extracellular lumen via a dynamin-1-dependent pathway in vitro. This also occurred in vivo, where injection of GFP-labeled mouse cortical neuronal stem cells into the hippocampus of α-synuclein-transgenic mice led to the efficient uptake of the host...