neurotoxin /no͝or′ōtok″sin/ [Gk, neuron + toxikon, poison] , a toxin that acts directly on the tissues of the central nervous system, traveling along the axis cylinders of the motor nerves to the brain. The toxin may be secreted in the venom of certain snakes, or it may be present on the spines of a shell or in the flesh of fish or shellfish; it may be produced by certain bacteria or by the cellular disintegration of certain bacteria.
