Historical neurotoxins: what we have learned from toxins of the past about diseases of the present.

Throughout history, humans have fallen victim to a variety of neurotoxins, with exposures coming in the form of tainted products, industrial pollution, drugs of abuse, and even the bread and water that sustain them. Despite this long and tumultuous history, neurotoxic outbreaks still occur with regular frequency. Although many difficulties currently exist in linking many of today's unexplained neurologic disorders to toxins, the past suggests a prominent role for neurotoxins in diseases (such as amyotrophic lateral sclerosis and PD), unexplained peripheral neuropathies, neurodevelopmental disorders, and many psychiatric disturbances.