Air Pollution Impairs Cognition, Provokes Depressive-like Behaviors, and Alters Hippocampal Cytokine Expression and Morphology


Molecular Psychiatry, (5 July 2011) | doi:10.1038/mp.2011.76

Air pollution impairs cognition, provokes depressive-like behaviors, and alters hippocampal cytokine expression and morphology

L K Fonken, X Xu, Z M Weil, G Chen, Q Sun, S Rajagopalan, and R J Nelson

The authors give the background for their study: “Particulate matter air pollution is a pervasive global risk factor implicated in the genesis of pulmonary and cardiovascular disease. Although the effects of prolonged exposure to air pollution are well characterized with respect to pulmonary and cardiovascular function, comparatively little is known about the impact of particulate matter on affective and cognitive processes. The central nervous system may be adversely affected by activation of reactive oxygen species and pro-inflammatory pathways that accompany particulate matter pollution. Thus, we investigated whether long-term exposure to ambient fine airborne particulate matter (<2.5 μm (PM2.5)) affects cognition, affective responses, hippocampal inflammatory cytokines [small cell-signaling protein molecules that are secreted by the glial cells of the nervous system and by numerous cells of the immune system], and neuronal morphology [form/structure].”

The methods and the results of the study were as follows: “Male mice were exposed to either PM2.5 or filtered air (FA) for 10 months. PM2.5 mice displayed more depressive-like responses and impairments in spatial learning and memory as compared with mice exposed to FA. Hippocampal pro-inflammatory cytokine expression was elevated among PM2.5 mice. Apical dendritic spine density and dendritic branching were decreased in the hippocampal CA1 and CA3 regions, respectively, of PM2.5 mice.”

The authors conclude, “Taken together, these data suggest that long-term exposure to particulate air pollution levels typical of exposure in major cities around the globe can alter affective responses and impair cognition.”

Hippocampus – “A major component of the brain in humans and mammals. It belongs to the limbic system and plays important roles in the consolidation of information from short-term memory to long-term memory and spatial navigation… In Alzheimer’s disease, the hippocampus is one of the first regions of the brain to suffer damage; memory problems and disorientation appear among the first symptoms.” (From: Wikipedia,

This entry was posted in Particulate Pollution and Brain Damage, Particulate Pollution and Cardiopulmonary Disease, Particulate Pollution and Cardiovascular Disease, Particulate Pollution and Cognition, Particulate Pollution and Cognitive Impairment, Particulate Pollution and Depression, Particulate Pollution and Inflammation, Particulate Pollution and Oxidative Stress and tagged , , , , , , , , , , , , , . Bookmark the permalink.

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