title: Effects of diesel engine exhaust origin secondary organic aerosols on novel object recognition ability and maternal behavior in BALB/c mice.
abstract: Epidemiological studies have reported an increased risk of cardiopulmonary and lung cancer mortality associated with increasing exposure to air pollution. Ambient particulate matter consists of primary particles emitted directly from diesel engine vehicles and secondary organic aerosols (SOAs) are formed by oxidative reaction of the ultrafine particle components of diesel exhaust (DE) in the atmosphere. However, little is known about the relationship between exposure to SOA and central nervous system functions. Recently, we have reported that an acute single intranasal instillation of SOA may induce inflammatory response in lung, but not in brain of adult mice. To clarify the whole body exposure effects of SOA on central nervous system functions, we first created inhalation chambers for diesel exhaust origin secondary organic aerosols (DE-SOAs) produced by oxidation of diesel exhaust particles caused by adding ozone. Male BALB/c mice were exposed to clean air (control), DE and DE-SOA in inhalation chambers for one or three months (5 h/day, 5 days/week) and were examined for memory function using a novel object recognition test and for memory function-related gene expressions in the hippocampus by real-time RT-PCR. Moreover, female mice exposed to DE-SOA for one month were mated and maternal behaviors and the related gene expressions in the hypothalamus examined. Novel object recognition ability and N-methyl-D-aspartate (NMDA) receptor expression in the hippocampus were affected in male mice exposed to DE-SOA. Furthermore, a tendency to decrease maternal performance and significantly decreased expression levels of estrogen receptor (ER)-α, and oxytocin receptor were found in DE-SOA exposed dams compared with the control. This is the first study of this type and our results suggest that the constituents of DE-SOA may be associated with memory function and maternal performance based on the impaired gene expressions in the hippocampus and hypothalamus, respectively.
authors.affiliation: Center for Environmental Health Sciences, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. tin.tin.win.shwe@nies.go.jp.
authors.forename: Tin-Tin
authors.initials: TT
authors.lastname: Win-Shwe
authors.affiliation: Center for Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. fujitani.yuji@nies.go.jp.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Fujitani
authors.affiliation: Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570, Japan.
authors.forename: Chaw
authors.initials: C
authors.lastname: Kyi-Tha-Thu
authors.affiliation: Center for Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. kawagoe@nies.go.jp.
authors.forename: Akiko
authors.initials: A
authors.lastname: Furuyama
authors.affiliation: Center for Environmental Health Sciences, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. tmichikawa@nies.go.jp.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Michikawa
authors.affiliation: Division of Life Science, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570, Japan. stsuka@mail.saitama-u.ac.jp.
authors.forename: Shinji
authors.initials: S
authors.lastname: Tsukahara
authors.affiliation: Center for Environmental Health Sciences, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. nitta@nies.go.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nitta
authors.affiliation: Center for Environmental Risk Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. seishiro@nies.go.jp.
authors.forename: Seishiro
authors.initials: S
authors.lastname: Hirano
mesh_terms: D000336:Aerosols / Q000633:toxicity*; D000393:Air Pollutants / Q000633:toxicity*; D000818:Animals; D005260:Female; D019570:Inhalation Exposure; D008297:Male; D008425:Maternal Behavior / Q000187:drug effects*; D008568:Memory / Q000187:drug effects*; D051379:Mice; D008807:Mice, Inbred BALB C; D010316:Particle Size; D052638:Particulate Matter / Q000633:toxicity; D001335:Vehicle Emissions / Q000633:toxicity*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter; D001335:Vehicle Emissions