CHAPTER 20 – Oxidative stress and neurodegeneration

Oxidative stress is characterized by the presence of an excess of oxidants caused by an imbalance between the formation and neutralization of reactive oxygen species. Oxidative stress can lead to the formation of chain reaction by-products, which create a potentially unstable cellular environment by causing massive cellular injury and extensive damage to the lipids, proteins, and biological macromolecules. Oxidative stress is also linked to tissue damage, advancing age associated dysfunctions, and a broad spectrum of degenerative diseases including neurodegeneration. Neurodegenerative disorders constitute one of the major challenges of modern medicine and health professionals. Although these diseases are relatively common and often highly debilitating, the mechanisms responsible for their pathologies are poorly understood, and there are currently no effective preventative or therapeutic strategies. Recent studies demonstrate that oxidative stress and oxidative DNA damage may be involved in the cytotoxicity of chlorpyrifos, fenthion, and other pesticides, as well as heavy metals. Neurotransmitter systems play a key role in behavioral function and disturbances, and structurally dissimilar pesticides and heavy metal significant disrupt the system.