Airborne inflammatory factors from the nose to the brain

Abstract

The intranasal pathway is a direct route of communication between the environment and the brain. This pathway is currently used for the delivery of several experimental therapeutic peptides and vaccines because it bypasses the blood brain barrier. It is also a route of entrance to the brain for several viruses and toxic substances. Airborne infectious, allergic and pollution agents are among the most common inflammatory factors which may affect brain function via the brain-nose interface. The inflammatory processes triggered in the upper respiratory tract by these agents are positioned to influence the immune response of the brain and therefore, influence its function and alter behavior. Several clinical and epidemiological studies find an association between inflammatory factors affecting the intranasal pathway and neurological disorders such as multiple sclerosis, Alzheimer and Parkinson diseases as well as mental disorders including anxiety and mood disorders. However the mechanisms of interaction between the immune response in the nasal epithelium and the brain are poorly understood. This article discusses current evidence about these mechanisms and associations with neurological and mental diseases.

Gene expression changes in rat brain after short and long exposures to particulate matter in Los Angeles basin air: Comparison with human brain tumors

“…Currently, it is well established that air pollution affects brain functions and can contribute to various brain pathologies, notably, neuroinflammation and neurodegeneration (Calderón-Garcidueñas et al, 2004, 2008a,b, 2012aBlock and Calderón-Garcidueñas, 2009;Campbell et al, 2009;Ljubimova et al, 2001;Genc et al, 2012;Block et al, 2012;Tonelli and Postolache, 2010;Levesque et al, 2011). A recent gene microarray study of autopsy frontal brain cortex tissues of pollution-exposed children and young adults revealed mostly upregulation of pro-inflammatory genes (Calderón-Garcidueñas et al, 2012a).…”

Ambient ozone and emergency department visits due to lower respiratory condition

“…that poor air quality, in the form of higher levels of ozone, may contribute to bronchitis exacerbations that require ED visits. Ozone may induce morphological and bio chemical effects in nasal and respiratory airways [15,16]. Airborne infectious, allergic and air pollution agents are among the most common inflammatory factors and ozone is among them.…”

Impact of the Airborne Particulate Matter onthe Human Health

“…About a decade ago, the CNS has also been proposed to be a target organ for the detrimental effects of airborne pollutants (Oberdörster and Utell, 2002). Emerging evidence from recent epidemiological, clinical, and experimental studies suggests that certain neurological diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and stroke, may be strongly associated with ambient air pollution (Tonelli and Postolache, 2012). Air pollutants affect the CNS either directly by transport of UFP into the CNS or through systemic inflammations.…”