Neurotoxin is a substance that alters the structure or function of the nervous system. A poisonous substance that acts on the nervous system and disrupts the normal function of nerve cells. Neurotoxins inhibit neuron control over ion concentrations across the cell membrane or communication between neurons across a synapse. Aspartame, Sucralose, Diacetyl, Monosodium Glutamate, Aluminum are some of the neurotoxins in food.