Recently, I've watched a documentary about how, in the 1980s, people were buying and using drugs from the streets and then becoming paralyzed a few days afterwards. The drugs that they were using were contaminated with a substance called MPTP, which was able to selectively destroy dopamine-producing cells in the brain, essentially causing end-stage Parkinson's Disease, but leaving higher cognitive functions intact. Is MPTP unique in its ability to selectively destroy a certain type of cell, or are there other substances that can selectively destroy certain body cells while leaving the others intact? If yes, then by what mechanism do they work?