In utero exposure to a low concentration of diesel exhaust affects spontaneous locomotor activity and monoaminergic system in male mice

Abstract

BackgroundEpidemiological studies have suggested that suspended particulate matter (SPM) causes detrimental health effects such as respiratory and cardiovascular diseases, and that diesel exhaust particles from automobiles is a major contributor to SPM. It has been reported that neonatal and adult exposure to diesel exhaust damages the central nervous system (CNS) and induces behavioral alteration. Recently, we have focused on the effects of prenatal exposure to diesel exhaust on the CNS. In this study, we examined the effects of prenatal exposure to low concentration of diesel exhaust on behaviour and the monoaminergic neuron system. Spontaneous locomotor activity (SLA) and monoamine levels in the CNS were assessed.MethodsMice were exposed prenatally to a low concentration of diesel exhaust (171 μg DEP/m3) for 8 hours/day on gestational days 2-16. SLA was assessed for 3 days in 4-week-old mice by analysis of the release of temperature-associated infrared rays. At 5 weeks of age, the mice were sacrificed and the brains were used for analysis by high-performance liquid chromatography (HPLC).Results and DiscussionMice exposed to a low concentration of diesel exhaust showed decreased SLA in the first 60 minutes of exposure. Over the entire test period, the mice exposed prenatally to diesel exhaust showed decreased daily SLA compared to that in control mice, and the SLA in each 3 hour period was decreased when the lights were turned on. Neurotransmitter levels, including dopamine and noradrenaline, were increased in the prefrontal cortex (PFC) in the exposure group compared to the control group. The metabolites of dopamine and noradrenaline also increased in the PFC. Neurotransmitter turnover, an index of neuronal activity, of dopamine and noradrenaline was decreased in various regions of the CNS, including the striatum, in the exposure group. The serum corticosterone level was not different between groups. The data suggest that decreased SLA in mice exposed prenatally to diesel exhaust is due to facilitated release of dopamine in the PFC.ConclusionsThese results indicate that exposure of mice in utero to a low concentration of diesel exhaust decreases SLA and alters the neurochemical monoamine metabolism of several regions of the brain.

Exposure to diesel exhaust during fetal period affects behavior and neurotransmitters in male offspring mice

“…Similar to our previous reports (Yokota et al, 2009;Suzuki et al, 2010), we detected decreased DA metabolites in the nucleus accumbens in DE-exposed male offspring (three-week-old, data not shown) in the dopamin-ergic system. DA and a DA metabolite, 3-MT, were decreased in the prefrontal cortex in DE-exposed mice at three weeks of age (DA; P = 0.034, 3-MT; P = 0.041, Fig.…”

“…In addition, serum testosterone concentration, a parameter of impulsive behavior such as aggression, was also increased by maternal exposure to DE (Yoshida et al, 2006). Furthermore, we showed that prenatal exposure to DE decreased locomotion as well as dopamine metabolites in the nucleus accumbens (Yokota et al, 2009), which was confirmed in a subsequent study (Suzuki et al, 2010).…”

Fetal exposure to diesel exhaust affects X-chromosome inactivation factor expression in mice

“…Behavioral changes related to monoamine in response to maternal inhalation of DE are also reported (Yokota et al, 2013). The exposure of mice in utero to 171 μg DEP/m 3 of DE decreases spontaneous locomotor activity and alters neurochemical monoamine metabolism in several brain regions (Suzuki et al, 2010). Several research studies of DE exposure have used microarray.…”

Effect of fetal exposure to titanium dioxide nanoparticle on brain development − brain region information

“…There are reports that inhaled or injected particulate matter enters the systemic circulation (Takenaka et al, 2001) and reaches various tissues including the brain . The hippocampus has been reported as a target region of the effects of fetal exposure to environmental particulate matter (diesel exhaust particles) in a pathological study (Sugamata et al, 2006a) and by the evaluation of monoamine levels (Suzuki et al, 2010). The cerebellum is another target of particulate matter including inhaled diesel exhaust particles (Sugamata et al, 2006b) and carbon nanoparticles (Oberdorster et al, 2004).…”