Particulate matter air pollution is a serious health risk factor and has been implicated in pulmonary and cardiovascular disease. In this study, Fonken and coworkers investigated whether the brain may also be adversely affected. They investigated whether long-term exposure to ambient fine airborne particulate matter (<2.5 μm (PM2.5)) affects cognition, affective responses, hippocampal inflammatory cytokines and brain neuronal morphology. Male mice were exposed to either PM2.5 or filtered air for 10 months. PM2.5 mice displayed more depressive-like responses and impairments in spatial learning and memory. Hippocampal proinflammatory cytokines were also elevated in mice exposed to PM2.5. Dendritic spine changes (reduced density and branching) were noted in the hippocampus of mice exposed to PM2.5. The authors suggest that long-term exposure to particulate air pollution (at levels typical of exposure in major cities around the globe) can alter behavioral responses and impair cognition.
Fonken LK, Xu X, Weil ZM, Chen G, Sun Q, Rajagopalan S and Nelson RJ: Air pollution impairs cognition, provokes depressive-like behaviors and alters hippocampal cytokine expression and morphology. Molecular Psychiatry 16: 987–995 (2011).