Neuroinflammation in Neurological Dysfunction and Degeneration

The inflammatory hypothesis states that neuroinflammation originating from infection, trauma, or toxicant exposures may alter brain immunohomeostasis, culminating in neurocircuitry dysfunction and progressive degeneration. Neuroinflammation can accelerate the progression of neurodegenerative diseases, yet many argue that although it is a necessary element, it is not a sufficient explanation for all of the features associated with neurodegenerative diseases—citing atypical disease-specific protein lesions, the failures of anti-inflammatory treatments, and prevalence mismatch for neurodegenerative diseases linked to infection or chronic inflammatory disorders. Thus, whether neuroinflammation in neurodegenerative diseases is pathogenic or exists to mitigate neuronal dysfunction and degeneration is still being debated. This chapter will evaluate the inflammatory hypothesis and provide insight into how environmentally derived neuroinflammation may alter neurological function and promote neuronal loss in neurodegenerative diseases.