Neurotoxins - Presignaptics and Post-Synaptic Neurotoxins

Neurotoxins that attack the nervous system can lead to respiratory paralysis and death. The two families of neurotoxins, if you like, go about it in different ways. A presynaptic neurotoxin does is on the transmitter sites on the upstream side of the synapse. With a post-synaptic neurotoxin, what the venom does is it gums up the receptor sites on the downstream side of theSynapse. If they're not reversed quickly enough by an anti-venom then there could be internal bleeding or even brain damage.