Congruence of Intranasal Aerodynamics and Functional Heterogeneity of Olfactory Epithelium

Abstract

Zonal organization of the olfactory system is determined not only by peculiarities of the expression of olfactory receptor genes but also by the geometry of nasal passage, where receptors to the most muco-soluble compounds are concentrated in the area with the maximal rate of air flow (dorsal part), while receptors to less volatile compounds are concentrated in ventral part of the nose. An increase in the flow rate in certain areas of nasal cavity, on the one hand, allows acceleration of the perception of odor stimuli by olfactory receptors and, on the other hand, increases the risk of the effect of different pathogens (contained in the air) on this area due to the larger intensity of their precipitation. In this study, we demonstrated by means of manganese- enhanced magnetic resonance imaging (MRI) that a more intensive capture of insoluble particles occurs in ventral part of mouse olfactory epithelium than in dorsal part during intranasal introduction of the colloid solution of manganese oxide nanoparticles (MON, Mn3O4). The joint introduction of MON and specific blockers of cellular transport and endocytosis demonstrated that the particles are captured from the nasal cavity by means of endocytosis and are transported in olfactory bulb cells by means of intracellular transport. The clathrin-dependent type of endocytosis mainly contributes to the capture of MON in the dorsal part of the olfactory epithelium (as opposed to ventral). Thus, it was established that two functional regions of mouse olfactory epithelium differing in the intensities of precipitation of submicron aerosols demonstrate different intensities of the capture of insoluble particles from the nasal cavity and have differences in the mechanisms of their endocytosis. Consequently, the structural and functional organization of mouse nasal cavity completely meets the principle of adaptive congruence, which limits infectious and toxic effects of nanoaerosols on the olfactory epithelium cells and the brain.