Nano-Sized Secondary Organic Aerosol of Diesel Engine Exhaust Origin Impairs Olfactory-Based Spatial Learning Performance in Preweaning Mice

作者：Win Shwe Tin Tin^*; Kyi Tha Thu Chaw; Moe Yadanar; Maekawa Fumihiko; Yanagisawa Rie; Furuyama Akiko; Tsukahara Shinji; Fujitani Yuji; Hirano Seishiro

来源：Nanomaterials, 2015, 5(3): 1147-1162.

DOI：10.3390/nano5031147

• developmental neurotoxicity
• diesel exhaust
• secondary organic aerosol
• olfactory-based learning
• preweaning mice
• hippocampus
• nanotoxicity

The aims of our present study were to establish a novel olfactory-based spatial learning test and to examine the effects of exposure to nano-sized diesel exhaust-origin secondary organic aerosol (SOA), a model environmental pollutant, on the learning performance in preweaning mice. Pregnant BALB/c mice were exposed to clean air, diesel exhaust (DE), or DE-origin SOA (DE-SOA) from gestational day 14 to postnatal day (PND) 10 in exposure chambers. On PND 11, the preweaning mice were examined by the olfactory-based spatial learning test. After completion of the spatial learning test, the hippocampus from each mouse was removed and examined for the expressions of neurological and immunological markers using real-time RT-PCR. In the test phase of the study, the mice exposed to DE or DE-SOA took a longer time to reach the target as compared to the control mice. The expression levels of neurological markers such as the N-methyl-d-aspartate (NMDA) receptor subunits NR1 and NR2B, and of immunological markers such as TNF-alpha, COX2, and Iba1 were significantly increased in the hippocampi of the DE-SOA-exposed preweaning mice as compared to the control mice. Our results indicate that DE-SOA exposure in utero and in the neonatal period may affect the olfactory-based spatial learning behavior in preweaning mice by modulating the expressions of memory function-related pathway genes and inflammatory markers in the hippocampus.

• 出版日期2015-9