Historical Neurotoxins: What We Have Learned from Toxins of the Past About Diseases of the Present

Responsible for our thoughts and actions, the nervous system, more thanany other organ system in the body, defines us as individuals. Although wellprotected from the environment by the unique capillary system known asthe blood-brain barrier, there are certain toxins that, nonetheless, spe-cifically target the central and peripheral nervous systems. Several featuresmake the nervous system uniquely susceptible to these toxins. Nerve cellsand neurons with their long dendrites and axons have a large surface areafor absorption and attack by chemicals. With a dry weight composed of50% lipid, the brain and nervous tissue are particularly vulnerable to fat-soluble toxins. Once injured, neurons and nerve tissue have a limited capac-ity to regenerate, placing the emphasis for treatment on prevention. Alongwith affecting the adult nervous system, toxins also can have profoundeffects on the developing nervous system, resulting in neurodevelopmentaldisorders [1].The increasing awareness of the neurotoxic potential of chemicals hasresulted in congressional [2] and public emphasis placed on identifying thosechemicals that have neurotoxic potential. In response to this increasedawareness, several animal and cellular models have been developed to rec-ognize neurotoxins better [3]. There are difficulties, however, in translating