scholarly journals Mapping the impact of exposure to maternal immune activation on juvenile Wistar rat brain macro- and microstructure during early post-natal development

2019 ◽  
Vol 3 ◽  
pp. 239821281988308
Author(s):  
Tobias C. Wood ◽  
Michelle E. Edye ◽  
Michael K. Harte ◽  
Joanna C. Neill ◽  
Eric P. Prinssen ◽  
...  

Maternal immune activation is consistently associated with elevated risk for multiple psychiatric disorders in the affected offspring. Related to this, an important goal of our work is to explore the impact of maternal immune activation effects across the lifespan. In this context, we recently reported the effects of polyriboinosinic-polyribocytidylic acid–induced maternal immune activation at gestational day 15, immediately prior to birth, at gestational day 21 and again at post-natal day 21, providing a systematic assessment of plasma interleukin 6, body temperature and weight alterations in pregnant rats and preliminary evidence for gross morphological changes and microglial neuropathology in both male and female offsprings at these time points. Here, we sought to complement and extend these data by characterising in more detail the mesoscale impact of gestational polyriboinosinic-polyribocytidylic acid exposure at gestational day 15 on the neuroanatomy of the juvenile (post-natal day 21) rat brain using high-resolution, ex vivo anatomical magnetic resonance imaging in combination with atlas-based segmentation. Our preliminary data suggest subtle neuroanatomical effects of gestational polyriboinosinic-polyribocytidylic acid exposure (n = 10) relative to saline controls (n = 10) at this time-point. Specifically, we found an increase in the relative volume of the diagonal domain in polyriboinosinic-polyribocytidylic acid offspring (p < 0.01 uncorrected), which just failed to pass stringent multiple comparisons correction (actual q = 0.07). No statistically significant microstructural alterations were detectable using diffusion tensor imaging. Further studies are required to map the proximal effects of maternal immune activation on the developing rodent brain from foetal to early post-natal life and confirm our findings herein.

2018 ◽  
Author(s):  
Tobias C. Wood ◽  
Michelle E. Edye ◽  
Michael K. Harte ◽  
Joanna C. Neill ◽  
Eric P. Prinssen ◽  
...  

AbstractMaternal immune activation (MIA) is consistently associated with elevated risk for multiple psychiatric disorders in the affected offspring. Related to this, an important goal of our work is to explore the impact of MIA effects across the lifespan. In this context, we recently reported the effects of poly (I:C)-induced MIA at gestational day (GD)15, immediately prior to birth, at GD21 and again at post-natal day (PD)21, providing a systematic assessment of plasma IL-6, body temperature and weight alterations in pregnant rats following poly (I:C) exposure and preliminary evidence for gross morphological changes and microglial neuropathology in both male and female offspring at GD21 and PD21. Here, we sought to complement and extend these data by characterising in more detail the meso-scale impact of gestational poly (I:C) exposure at GD15 on the neuroanatomy of the juvenile (PD21) rat brain using high-resolution, ex vivo anatomical magnetic resonance imaging (MRI) in combination with atlas-based segmentation. Our preliminary data suggest subtle neuroanatomical effects of gestational poly (I:C) exposure (n=10) relative to saline controls (n=10) at this time-point. Specifically, we report here preliminary evidence for a significant increase in the relative volume of the diagonal domain in poly (I:C) offspring (p<0.01; q<0.1), particularly in female offspring. This occurred in the absence of any microstructural alterations as detectable using diffusion tensor imaging (DTI). Longitudinal in vivo studies, informed by the effect sizes from this dataset are now required to establish both the functional relevance and cellular mechanisms of the apparent DD volume increase.


2021 ◽  
Author(s):  
Elisa Guma ◽  
Emily Snook ◽  
Shoshana Spring ◽  
Jason P Lerch ◽  
Brian J Nieman ◽  
...  

Prenatal exposure to maternal immune activation (MIA) is a risk factor for a variety of neurodevelopmental and psychiatric disorders. The timing of MIA-exposure has been shown to affect adolescent and adult offspring neurodevelopment, however, less is known about these effects in the neonatal period. To better understand the impact of MIA-exposure on neonatal brain development, we first assess neonate communicative abilities with the ultrasonic vocalization task, followed by high-resolution ex vivo magnetic resonance imaging (MRI) on the neonatal (postnatal day 8) brain. Early exposed offspring displayed decreased communicative ability, while brain anatomy appeared largely unaffected, apart from some subtle alterations. By integrating MRI and behavioural assays to investigate the effects of MIA-exposure on neonatal neurodevelopment we show that offspring neuroanatomy and behaviour are only subtly affected by both early and late exposure. This suggests that the deficits often observed in later stages of life may be dormant, not yet developed in the neonatal period, or not as easily detectable using a cross-sectional approach.


2021 ◽  
Vol 11 (3) ◽  
pp. 344
Author(s):  
Kinga Gzielo ◽  
Agnieszka Potasiewicz ◽  
Ewa Litwa ◽  
Diana Piotrowska ◽  
Piotr Popik ◽  
...  

Prenatal maternal infection is associated with an increased risk of various neurodevelopmental disorders, including autism spectrum disorders (ASD). Maternal immune activation (MIA) can be experimentally induced by prenatal administration of polyinosinic:polycytidylic acid (poly I:C), a synthetic viral-like double-stranded RNA. Although this MIA model is adopted in many studies, social and communicative deficits, included in the first diagnostic criterion of ASD, are poorly described in the offspring of poly(I:C)-exposed dams. This study aimed to characterize the impact of prenatal poly(I:C) exposure on socio-communicative behaviors in adolescent rats. For this purpose, social play behavior was assessed in both males and females. We also analyzed quantitative and structural changes in ultrasonic vocalizations (USVs) emitted by rats during the play test. Deficits of social play behaviors were evident only in male rats. Males also emitted a significantly decreased number of USVs during social encounters. Prenatal poly(I:C) exposure also affected acoustic call parameters, as reflected by the increased peak frequencies. Additionally, repetitive behaviors were demonstrated in autistic-like animals regardless of sex. This study demonstrates that prenatal poly(I:C) exposure impairs socio-communicative functioning in adolescent rats. USVs may be a useful tool for identifying early autistic-like abnormalities.


2020 ◽  
Vol 1 (1) ◽  
pp. 24-26
Author(s):  
Kazuhiro Sakurada ◽  
Yoshihiro Noda

As of summer 2020, the COVID-19 pandemic is having a major impact on our daily lives on a global scale, forcing us to change to the new normal. However, the effects are not only detrimental to our present socioeconomic conditions but also have the risk of having negative biological effects on our descendants. Of concern is the effect of maternal immune activation following maternal infection with COVID-19 on the fetus’ cerebral nervous system. While we are currently occupied with countering the imminent threats in front of us, we also need to take steps from a public health perspective to reduce the impact of maternal infection on the fetus, especially the risk of neurodevelopmental disorders. However, such a risk can be prevented and managed through the digital transformation of the nation’s health data and the strategic application of sophisticated data science approaches to those big data.


2017 ◽  
Author(s):  
Sila Genc ◽  
Charles B Malpas ◽  
Gareth Ball ◽  
Timothy J Silk ◽  
Marc L Seal

AbstractPurposeThe corpus callosum is integral to the central nervous system, and continually develops with age by virtue of increasing axon diameter and ongoing myelination. Magnetic resonance imaging (MRI) techniques offer a means to disentangle these two aspects of white matter development. We investigate the profile of microstructural metrics across the corpus callosum, and assess the impact of age, sex and pubertal development on these processes.MethodsThis study made use of two independent paediatric populations. Multi-shell diffusion MRI data were analysed to produce a suite of diffusion tensor imaging (DTI), neurite orientation density and dispersion imaging (NODDI), and apparent fibre density (AFD) metrics. A multivariate profile analysis was performed for each diffusion metric across 10 subdivisions of the corpus callosum.ResultsAll diffusion metrics significantly varied across the length of the corpus callosum. AFD exhibited a strong relationship with age across the corpus callosum (partial η2 = .65), particularly in the posterior body of the corpus callosum (partial η2 = .72). In addition, females had significantly higher AFD compared with males, most markedly in the anterior splenium (partial η2 = .14) and posterior genu (partial η2 = .13). Age-matched pubertal group differences were localised to the splenium.ConclusionWe present evidence of a strong relationship between apparent fibre density and age, sex, and puberty during development. These results are consistent with ex vivo studies of fibre morphology, providing insights into the dynamics of axonal development in childhood and adolescence using diffusion MRI.Target journalsBrain Structure & Function; HBM; NeuroImage; Developmental Cognitive Neuroscience


2017 ◽  
Vol 63 ◽  
pp. 50-59 ◽  
Author(s):  
William R. Crum ◽  
Stephen J. Sawiak ◽  
Winfred Chege ◽  
Jonathan D. Cooper ◽  
Steven C.R. Williams ◽  
...  

2021 ◽  
Author(s):  
Elisa Guma ◽  
Maude Bordeleau ◽  
Emily Snook ◽  
Gabriel Desrosiers-Gregoire ◽  
Fernando Gonzalez Ibanez ◽  
...  

Exposure to maternal immune activation (MIA) in utero is a risk factor for neurodevelopmental and psychiatric disorders. MIA-induced deficits in adolescent and adult offspring have been well characterized, however, less is known about the effects of MIA-exposure on embryo development. To address this gap, we performed high-resolution ex vivo magnetic resonance imaging (MRI) to investigate the effects of early (gestational day [GD]9) and late (GD17) MIA-exposure on embryo (GD18) brain structure. We identify striking neuroanatomical changes in the embryo brain, particularly in the late exposed offspring. We further examined hippocampal neuroanatomy using electron microscopy and identified differential effects due to MIA-timing. An increase in apoptotic cell density was observed in the GD9 exposed offspring, while an increase in the density of dark neurons and glia, putative markers for increased neuroinflammation and oxidative stress, was observed in GD17 exposed offspring, particularly in females. Overall, our findings integrate imaging techniques across different scales to identify differential impact of MIA-timing on the earliest stages of neurodevelopment.


2021 ◽  
Author(s):  
◽  
Alexandra Lister

<p>Maternal Immune Activation (MIA) during early pregnancy is an established risk factor for the occurrence of neurodevelopmental disorders such as Autism Spectrum Disorder (ASD) and schizophrenia (SCZ) in offspring. Serotonin signalling is also implicated in both ASD and SCZ, in conjunction with a known and extensive influence in neural development. Using a Wistar serotonin transporter (SERT) knockout model to mimic allelic variation in the human serotonin transporter promoter (5‐HTTLPR), this research investigates the impact of full or reduced SERT function on the effect of poly I:C-induced MIA in offspring. Experimental design focuses on ultrasonic vocalisation communication in postnatal day (PND) 7 offspring, followed by genetic expression of the Rac1/Kal7/Disc1 signalosome pathway at PND21 previously implicated in SCZ pathology. Results from behavioural analysis of pups indicate a statistically significant increase in calling and call complexity in pups heterozygous for the SERT (SERT HET) compared to wildtype (WT). When separated by sex, this trend remains consistent however only reaches significance in male offspring. Male SERT HET pups also a significant treatment effect in call complexity, and a significant genotype/treatment interaction which suggests an increased susceptibility to MIA-induced behavioural effects. Additionally, poly I:C exposed pups show increased expression of Disc1, supporting evidence that this pathway may be affected in neurodevelopmental disorders. No genotype and sex effects were observed in signalosome expression; however, this study may be too underpowered to detect these effects. These results suggest that differences between sex and SERT genotype in offspring may modulate the behavioural effects of MIA in rodent models of NDD, with more study required to assess these differences in a molecular context. Furthermore, this study aims to address the overall inconsistency and misrepresentation of statistical methods in MIA models by employing MIA validation tests and linear mixed modelling to account for litter variation. In summary, the research presented in this thesis reports initial evidence suggesting SERT genotype may influence the effect of MIA, however further research is necessary to characterise the effect of genotype on MIA challenge during gestation.</p>


2021 ◽  
Author(s):  
◽  
Alexandra Lister

<p>Maternal Immune Activation (MIA) during early pregnancy is an established risk factor for the occurrence of neurodevelopmental disorders such as Autism Spectrum Disorder (ASD) and schizophrenia (SCZ) in offspring. Serotonin signalling is also implicated in both ASD and SCZ, in conjunction with a known and extensive influence in neural development. Using a Wistar serotonin transporter (SERT) knockout model to mimic allelic variation in the human serotonin transporter promoter (5‐HTTLPR), this research investigates the impact of full or reduced SERT function on the effect of poly I:C-induced MIA in offspring. Experimental design focuses on ultrasonic vocalisation communication in postnatal day (PND) 7 offspring, followed by genetic expression of the Rac1/Kal7/Disc1 signalosome pathway at PND21 previously implicated in SCZ pathology. Results from behavioural analysis of pups indicate a statistically significant increase in calling and call complexity in pups heterozygous for the SERT (SERT HET) compared to wildtype (WT). When separated by sex, this trend remains consistent however only reaches significance in male offspring. Male SERT HET pups also a significant treatment effect in call complexity, and a significant genotype/treatment interaction which suggests an increased susceptibility to MIA-induced behavioural effects. Additionally, poly I:C exposed pups show increased expression of Disc1, supporting evidence that this pathway may be affected in neurodevelopmental disorders. No genotype and sex effects were observed in signalosome expression; however, this study may be too underpowered to detect these effects. These results suggest that differences between sex and SERT genotype in offspring may modulate the behavioural effects of MIA in rodent models of NDD, with more study required to assess these differences in a molecular context. Furthermore, this study aims to address the overall inconsistency and misrepresentation of statistical methods in MIA models by employing MIA validation tests and linear mixed modelling to account for litter variation. In summary, the research presented in this thesis reports initial evidence suggesting SERT genotype may influence the effect of MIA, however further research is necessary to characterise the effect of genotype on MIA challenge during gestation.</p>


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