Many<unk> s are potent neurotoxins, functioning by inhibiting the action of acetylcholinesterase (AChE) in nerve cells.  They are one of the most common causes of poisoning worldwide, and are frequently intentionally used in suicides in agricultural areas.
Organophosphate poisoning
Strychnine poisoning
Cyanide poisoning
Carbon monoxide poisoning
Nicotine poisoning
Arsenic poisoning
Mercury poisoning
Gold poisoning