| Author: | Ahadullah |
| Title: | Maternal exposure to air pollutant PM2.5 induces autistic-like behavior in adult offspring mice |
| Advisors: | Yau, Sonata (RS) |
| Degree: | M.Phil. |
| Year: | 2022 |
| Subject: | Autism spectrum disorders Air -- Pollution -- Health aspects Pregnant women Hong Kong Polytechnic University -- Dissertations |
| Department: | Department of Rehabilitation Sciences |
| Pages: | 73 pages : color illustrations |
| Language: | English |
| Abstract: | Autism spectrum disorders (ASD) is a neurodevelopmental condition with heterogeneous etiology. Core behavioral deficits commonly exhibited by individuals with ASD include impaired social communication and interaction skills, repetitive behavior, and intellectual disability with wide degrees of severity among individuals. ASD not only hinders an individual’s physical and psychological development, it also adversely affects their families’ daily life. Numerous studies undertaken in Asia, Europe, and North America have estimated the incidence rate of ASD to be between 1% and 2%, with a higher frequency in males than in females (4:1). Emerging studies have indicated the significant influence of environmental factors on increasing ASD susceptibility. According to a recent study, approximately 20% of 215 ASD candidate genes are epigenetic regulators, highlighting the importance of the interaction between genetic and environmental variables on the etiology of ASD. It has been speculated that gene and environment interactions are contributors to the increased prevalence of ASD. Amongst the various environmental factors, the surge in air pollutants in the environment is an emerging concern. Epidemiological studies have divulged into the relationship between long-term prenatal or postnatal exposure to hazardous air pollutants being potentially linked to ASD. Ambient air pollutant particulate matter (PM) has been associated with adversely affecting neurodevelopment. Prenatal and postnatal exposure to PM with sizes less than 2.5 µm (PM2.5) is significantly correlated with an increased risk of ASD, suggesting the potential role of PM2.5 exposure in increasing ASD susceptibility. Maternal exercise has been suggested that a long-lasting improvement and transgenerational neuroplasticity could be induced by maternal exercise in human brains. In this project, I aim to investigate the potential effects of maternal exposure to PM2.5 on causing autism-like behaviors in offspring, and to examine whether maternal running could protect the offspring from developing autistic phenotypes. The results have revealed that maternal exposure to PM2.5 induced core ASD behavior, including impaired social recognition memory and increased repetitive behavior, as well as, impairment in hippocampal dependent learning and memory performance. Maternal running was able to reverse core ASD-like behavior including social recognition memory and repetitive behavior, but not learning and memory impairment. The results also showed that maternal exposure to PM2.5 impaired the dendritic development of immature neurons in the hippocampal dentate gyrus but did not affect hippocampal neurogenesis and neuroinflammation. I hypothesize it may be due to difference in maturation and integration into neural circuitry as indicated by the reduction in total dendritic length of immature neurons in offspring with maternal PM2.5 exposure. Other mechanisms including changes in oxidative stress, gene expression and gut microbiota profile could also play a role in underlying behavioral deficits as we observed in our model. The underlying mechanisms warrant further investigation. |
| Rights: | All rights reserved |
| Access: | open access |
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