Neurotoxins

• What are neuro toxins?

Neurotoxins are substances or chemical agents that are poisonous to the neurons and inhibit them from functioning adequately. Neurotoxins can work in multiple ways, depending on the nature of the neurotoxin and the dosage. They may affect any step of the neural transmission [1].

• How are they delivered/ what are some sources

The body itself produce neurotoxins. Some of the neurotransmitters produced to transmit signal through the nervous system can be harmful in high amounts. Neurotoxins are also present in the natural environment, for example heavy metals like Mercury acts like a neurotoxin; while some venomous animals also produce neurotoxins [2].

Neurotoxins coming from external agents can be delivered to the body in many ways. Those agents coming from venomous animals are delivered to the nervous systems when a person is bitten by the animal, or when the animal’s preparation for human consumption is not properly done. Neurotoxins from other sources like the heavy metals can also be delivered to the body by its consumption; they can be present in the body of other animals and plant food [2].  

• How do they affect cell membranes with a particular emphasis on the nervous system?

As said before, neurotoxins may affect any step of the neural transmission. The inhibition process can range from interneuron communication, to cell membrane depolarization. At the scale of the cell membrane, there are some neurotoxins that inhibit the ion channels. Specific neurotoxins affect particular ion channels; for example Tetrodotoxin (TTX) is a neurotoxin present in the body of some marine fish. TTX affects the Ion channels, these channels are sensitive to the presence of TTX; the neurotoxin binds to the binding places of the sodium, preventing the ion to bind. In consequence, the transmission of the action potential is restricted. The exposure to TTX is fatal in most cases [2].