Lead (Pb)-Induced Neuroinflammation in the Developing and Aging Brain

Dysregulation of neuroinflammation has been implicated as a key mechanism in the etiology of several conditions of both a developmental and degenerative nature. Neuroinflammation is also one of the main mechanisms by which contamination with certain environmental pollutants—like lead (Pb)—disrupts the central nervous system (CNS), leading to significant neurological damage. A growing body of evidence indicates a potential link between lead exposure to the onset of neurodevelopmental disorders—such as Autism Spectrum Disorders (ASD) and Attention Deficit/Hyperactivity Disorder (ADHD)—and neurodegenerative conditions, like those observed in Parkinson’s disease (PD) and Alzheimer’s disease (AD). Important pathways have been identified in the context of lead exposure and association with neurological conditions; however, the precise mechanisms by which lead-induced neuroinflammation might be associated with these conditions are largely unknown. Inflammation of the CNS can be considered a key element in the convergence of lead-induced neuroinflammation and neurodevelopmental and neurodegenerative conditions. This review contextualizes aspects of neuroinflammatory responses upon lead exposure and discusses how these disruptions overlap with the onset of neurodevelopmental disorders, such as ASD and ADHD, and neurodegenerative diseases, such as PD and AD. We focus on recent developments in the field of neuroinflammation within these different contexts and discuss different hypotheses, sex as a biological variable, and areas in need of further investigation.