By A Midwestern Doctor
The Forgotten Side of Medicine
April 23, 2026
Parkinson's Disease
Parkinson's disease results from the progressive loss of dopamine-producing neurons in the substantia nigra. Research in this field was revolutionized in the early 1980s when recreational drug users who injected a badly synthesized synthetic heroin rapidly developed severe Parkinson's-like symptoms due to it being contaminated with MPTP, an agent whose active metabolite (MPP+) specifically targeted those neurons, making it possible to reliably model Parkinson's in laboratory animals.