Look at this azalea garden in the Bronx. Every flower in the frame contains grayanotoxin, the neurotoxin that took down a Roman column under Pompey in 65 BC. The mechanism is wild. Grayanotoxin binds Site 2 of voltage-gated sodium channels. Normally those channels open for a millisecond, fire an action potential, and snap shut. Grayanotoxin prevents the snap shut. Channels stay open. Sodium pours in. The neuron fires and cannot stop. The body experiences that as bradycardia, hypotension,…