Crystal structures show that botulinum toxins bind simultaneously to two sites on neurons. ... Schiavo, G. Dangerous liaisons on neurons. Nature 444, 1019–1020 (2006) . https://doi ...

An excitatory synapse is a structure in which two adjacent neurons — termed the presynaptic and postsynaptic neurons — communicate using a neurotransmitter molecule, usually glutamate (Fig. 1).