"It's still not clear exactly why or how the changes seen in Parkinson's spread from cell to cell in the brain, but researchers believe the alpha-synuclein protein may play a central role. "Alpha-synuclein is the main protein found inside the sticky protein clumps that appear inside the nerve cells affected in Parkinson's. Alpha-synuclein is the main protein found inside the sticky protein clumps that appear inside the nerve cells affected in Parkinson'. "It is becoming clear that more cells get these protein clumps the longer people have Parkinson's. "And these clumps seem to be passed from one brain cell to the next. We wanted to understand how alpha-synuclein clumps spread and affect more brain cells."

"We have discovered that alpha-synuclein may escape affected cells by hitching a ride in "exosomes" – small capsules that are released by cells. It is thought that the usual role of these exosomes is to shuttle messages from one cell to another

http://www.parkinsons.org.uk/content...move-cell-cell