Migrating immune cells promote nerve cell demise in the brain

The death of dopamine-producing nerve cells in a certain region of the brain is the principal cause underlying Parkinson's disease. In mice, it is possible to simulate the Parkinson's symptoms using a substance that selectively kills dopamine-producing neurons. Scientists have now shown that after this treatment, cells of the peripheral immune system migrate into the brain, where they play a major role in the death of neurons.