Sex steroid action is critical to form sexually dimorphic nuclei, although it is not fully understood. We previously reported that masculinization of the principal nucleus of the bed nucleus of the stria terminalis (BNSTp), which is larger and has more neurons in males than in females, involves aromatized testosterone that acts via estrogen receptor-α (ERα), but not estrogen receptor-β (ERβ). Here, we examined sex steroid action on the formation of the anteroventral periventricular nucleus (AVPV) that is larger and has more neurons in females. Morphometrical analysis of transgenic mice lacking aromatase, ERα, or ERβ genes revealed that the volume and neuron number of the male AVPV were significantly increased by deletion of aromatase and ERα genes, but not the ERβ gene. We further examined the AVPV and BNSTp of androgen receptor knockout (ARKO) mice. The volume and neuron number of the male BNSTp were smaller in ARKO mice than those in wild-type mice, while no significant effect of ARKO was found on the AVPV and female BNSTp. We also examined aromatase, ERα, and AR mRNA levels in the AVPV and BNSTp of wild-type and ARKO mice on embryonic day (ED) 18 and postnatal day (PD) 4. AR mRNA in the BNSTp and AVPV of wild-type mice was not expressed on ED18 and emerged on PD4. In the AVPV, the aromatase mRNA level was higher on ED18, although the ERα mRNA level was higher on PD4 without any effect of AR gene deletion. Aromatase and ERα mRNA levels in the male BNSTp were significantly increased on PD4 by AR gene deletion. These results suggest that estradiol signaling via ERα during the perinatal period and testosterone signaling via AR during the postnatal period are required for masculinization of the BNSTp, whereas the former is sufficient to defeminize the AVPV.

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social communication, poor social interactions and repetitive behaviors. The exact cause and mechanism of autism remains unknown. Both genetic and environmental factors may involve in ASD. In this study, we used diesel exhaust origin secondary organic aerosol (DE-SOA) as environmental pollutants. The aim of present study is to examine autism-like behaviors and related gene expressions in rats exposed to DE-SOA perinatally. Sprague-Dawley pregnant rats were exposed to clean air (control), diesel exhaust (DE) and DE-SOA in the exposure chamber for 5 h per day, 5days a week from gestational day 8 to postnatal day 21. At postnatal day 21, the male and female offspring rats were allocated into three different groups as follows: 1) rats exposed to clean filtered air; 2) rats exposed to DE; 3) rats exposed to DE-SOA. Social behaviors were investigated at 10~13-weeks-old rats using a 3-chambered social behavior test, social dominance tube test and marble burying test. Prefrontal cortex was collected under deep anesthesia to examine neurological and immunological markers, glutamate concentration, mast cell and microglia activation using real-time RT-PCR method, ELISA method and immunohistochemical analysis. Results: DE-SOA-exposed male and female rats showed poor sociability and social novelty preference, socially dominant behavior and increased repetitive behavior compared with the control rats. The mRNA expression levels of serotonin receptor (5-HT(5B)) and brain-derived neurotrophic factor (BDNF) were down-regulated whereas interleukin 1 b　(IL-b), and heme oxygenase 1 (HO-1) were upregulated in the prefrontal cortex of male and female rats exposed to DE-SOA compared to the control rats. In addition, the expression of mast cells and microglia marker ionized calcium-binding adapter molecule (Iba)1 were increased in the prefrontal cortex of male and female rats exposed to DE-SOA. Glutamate concentration was increased significantly in the prefrontal cortex of both male and female rats exposed to DE-SOA. Conclusion: Our results indicate that perinatal exposure to DE-SOA may induce autism-like behavior in rats by modulating neurological and immunological markers in the prefrontal cortex.

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social communication, poor social interactions and repetitive behaviors. The exact cause and mechanism of autism remains unknown. Both genetic and environmental factors may involve in ASD. In this study, we used diesel exhaust (DE) origin secondary organic aerosol (DE-SOA) as environmental pollutants. DE-SOA was generated by oxidative reaction of mixing DE with ozone. The aim of present study is to examine autism-like behaviors and related gene expressions in rats exposed to DE-SOA perinatally. Sprague-Dawley pregnant rats were exposed to clean air (control), DE and DE-SOA in the exposure chamber for 5 h per day (from 10:00 pm to 3:00 am), 5 days a week excluding weekends from gestational day 14 to postnatal day 21 with their pups. At postnatal day 21, the male and female offspring rats were allocated into three different groups as follows: 1) rats exposed to clean filtered air; 2) rats exposed to DE; 3) rats exposed to DE-SOA. Social behaviors were investigated at 10~13-weeks-old rats using a 3-chambered social behavior test, social dominance tube test and marble burying test. Prefrontal cortex was collected to examine neurological and immunological markers, and glutamate concentration, using real-time RT-PCR and ELISA methods. Results: DE-SOA-exposed male and female rats showed poor sociability and social novelty preference, socially dominant behavior and increased repetitive behavior compared with the control rats. The mRNA expression levels of serotonin receptor (5-HT(5B)) and brain-derived neurotrophic factor (BDNF) were down-regulated whereas interleukin 1 b　(IL-b), and heme oxygenase 1 (HO-1) were upregulated in the prefrontal cortex of male and female rats exposed to DE-SOA compared to the control rats. Glutamate concentration was increased significantly in the prefrontal cortex of both male and female rats exposed to DE-SOA.Conclusion: Our results indicate that perinatal exposure to DE-SOA may induce autism-like behavior in rats by modulating neurological and immunological markers in the prefrontal cortex.

Background Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impaired social communication, social interactions and repetitive behaviors. The etiology of autism remains unknown and its molecular basis is not well understood. Both genetic and environmental factors may contribute ASD. In this study, we used diesel exhaust origin secondary organic aerosol (DE-SOA) as environmental pollutants. The aim of present study is to examine autism-like behaviors and related gene expressions in rats exposed to DE-SOA perinatally. Sprague-Dawley pregnant rats were exposed to clean air (control), diesel exhaust (DE) and DE-SOA in the exposure chamber for 5 h per day, 5days a week from gestational day 8 to postnatal day 21. At postnatal day 21, the male and female offspring rats were allocated into three different groups as follows: 1) rats exposed to clean filtered air; 2) rats exposed to DE; 3) rats exposed to DE-SOA. Social behaviors were investigated at 10 ~ 13-weeks-old rats using a 3-chambered social behavior test, social dominance tube test and marble burying test. Prefrontal cortex was collected under deep anesthesia to examine neurological and immunological markers, glutamate concentration, mast cell and microglia activation using real-time RT-PCR method, ELISA method and immunohistochemical analysis. Results DE-SOA-exposed male and female rats showed poor sociability and social novelty preference, socially dominant behavior and increased repetitive behavior compared with the control rats. The mRNA expression levels of serotonin receptor (5-HT(5B)) and brain-derived neurotrophic factor (BDNF) were down-regulated whereas interleukin 1 β (IL-β), and heme oxygenase 1 (HO-1) were upregulated in the prefrontal cortex of male and female rats exposed to DE-SOA compared to the control rats. In addition, the expression of mast cells and microglia marker ionized calcium-binding adapter molecule (Iba)1 were increased in the prefrontal cortex of male and female rats exposed to DE-SOA. Glutamate concentration was increased significantly in the prefrontal cortex of both male and female rats exposed to DE-SOA. Conclusion Our results indicate that perinatal exposure to DE-SOA may induce autism-like behavior in rats by modulating neurological and immunological markers in the prefrontal cortex.

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