Long-term influence of normal variation in neonatal characteristics on human brain development

Effects of early institutionalization involving psychosocial deprivation on cognitive functioning 60 years later: Findings of the LifeStories project

BACKGROUND

Institutionalization involving psychosocial deprivation affects child development negatively. However, there are few longitudinal studies, and no prospective study has yet examined the consequences of institutionalization in late adulthood.

OBJECTIVE

Investigating effects of psychosocial deprivation on cognitive functioning 60 years later.

PARTICIPANTS AND SETTING

A population-based survey of institutionalized infants and toddlers was conducted in Switzerland from 1958 to 1961 (n = 387; Mage = 0.93 years, SD = 0.53, 48 % female, 48 % Swiss nationality). In parallel, a comparison group of 399 family-raised children were assessed (Mage = 0.85 years, SD = 0.50, 46 % female, 100 % Swiss nationality). Six decades later, data on cognitive functioning were collected for 88 of the institutionalized group (Mage = 62.63 years, SD = 1.32), and 148 of the comparison group (Mage = 65.06, SD = 1.32).

METHODS

Standardized tests were used: the Brunet-Lézine Developmental Test in early childhood and a short form of the Wechsler Adult Intelligence Scale in late adulthood.

RESULTS

Formerly institutionalized individuals scored lower on cognitive functioning (d = - 0.67, p < .001), with the greatest difference in working memory (d = -0.78, p < .001). Longer duration of institutionalization increased the risk of lower cognitive functioning, indicating a dose-response effect. Institutionalization's impact on adult cognitive functioning was mediated by early childhood developmental status but not by later educational attainment.

CONCLUSIONS

This study confirms the early experience hypothesis, indicating that early life conditions have lasting effects on human development, even into late adulthood.

Trajectories of brain and behaviour development in the womb, at birth and through infancy

Birth is often seen as the starting point for studying effects of the environment on human development, with much research focused on the capacities of young infants. However, recent imaging advances have revealed that the complex behaviours of the fetus and the uterine environment exert influence. Birth is now viewed as a punctuate event along a developmental pathway of increasing autonomy of the child from their mother. Here we highlight (1) increasing physiological autonomy and perceptual sensitivity in the fetus, (2) physiological and neurochemical processes associated with birth that influence future behaviour, (3) the recalibration of motor and sensory systems in the newborn to adapt to the world outside the womb and (4) the effect of the prenatal environment on later infant behaviours and brain function. Taken together, these lines of evidence move us beyond nature-nurture issues to a developmental human lifespan view beginning within the womb.

Fetal influence on the human brain through the lifespan

Human fetal development has been associated with brain health at later stages. It is unknown whether growth in utero, as indexed by birth weight (BW), relates consistently to lifespan brain characteristics and changes, and to what extent these influences are of a genetic or environmental nature. Here we show remarkably stable and lifelong positive associations between BW and cortical surface area and volume across and within developmental, aging and lifespan longitudinal samples (N = 5794, 4-82 y of age, w/386 monozygotic twins, followed for up to 8.3 y w/12,088 brain MRIs). In contrast, no consistent effect of BW on brain changes was observed. Partly environmental effects were indicated by analysis of twin BW discordance. In conclusion, the influence of prenatal growth on cortical topography is stable and reliable through the lifespan. This early-life factor appears to influence the brain by association of brain reserve, rather than brain maintenance. Thus, fetal influences appear omnipresent in the spacetime of the human brain throughout the human lifespan. Optimizing fetal growth may increase brain reserve for life, also in aging.

Impact of low birth weight on academic attainment during adolescence: A comprehensive retrospective cohort study using linked data

BACKGROUND

This study addresses a critical knowledge gap by exploring the intricate relationship between low birth weight (LBW) and the heightened risk of suboptimal academic achievement during adolescence through a comprehensive retrospective cohort design.

METHODS

In this registry-based cohort study, meticulously linked health and curriculum-based test data for individuals born in New South Wales (NSW), Australia, between 2003 and 2005 were employed. Birth weight data were carefully sourced from the NSW perinatal data collection (PDC). The educational performance of offspring was thoroughly evaluated using the National Assessment Program for Literacy and Numeracy (NAPLAN) during grade 9, approximately at 14 years of age.

RESULTS

After rigorous adjustments for potential confounders, findings revealed a compelling narrative: LBW adolescents demonstrated an elevated susceptibility to not meeting national minimum standards across all domains, encompassing spelling [OR, 1.59 (95%CI 1.48-1.69)], writing [OR, 1.51 (95%CI 1.41-1.61)], reading [OR, 1.38 (95%CI 1.29-1.48)], and numeracy [OR, 1.52 (95%CI 1.40-1.63)]. Notably, LBW boys exhibited a more pronounced inclination towards diminished academic performance compared to their female counterparts.

CONCLUSIONS

This comprehensive retrospective cohort study, based on linked data, unequivocally establishes LBW as significantly associated with an increased vulnerability to substandard educational achievement during adolescence. Particularly robust effects were observed in females across all outcomes. Aimed at investigating whether LBW serves as a predictive factor for later academic difficulties, this study underscores the imperative for the adoption and fortification of preventative and early intervention strategies to curtail the prevalence of LBW-associated academic underachievement in later adolescence.

Timing of lifespan influences on brain and cognition

Modifiable risk and protective factors for boosting brain and cognitive development and preventing neurodegeneration and cognitive decline are embraced in neuroimaging studies. We call for sobriety regarding the timing and quantity of such influences on brain and cognition. Individual differences in the level of brain and cognition, many of which present already at birth and early in development, appear stable, larger, and more pervasive than differences in change across the lifespan. Incorporating early-life factors, including genetics, and investigating both level and change will reduce the risk of ascribing undue importance and causality to proximate factors in adulthood and older age. This has implications for both mechanistic understanding and prevention.

The p factor of psychopathology and personality in middle childhood: genetic and gestational risk factors

BACKGROUND

A joint, hierarchical structure of psychopathology and personality has been reported in adults but should also be investigated at earlier ages, as psychopathology often develops before adulthood. Here, we investigate the joint factor structure of psychopathology and personality in eight-year-old children, estimate factor heritability and explore external validity through associations with established developmental risk factors.

METHODS

Phenotypic and biometric exploratory factor analyses with bifactor rotation on genetically informative data from the Norwegian Mother, Father, and Child Cohort (MoBa) study. The analytic sub-sample comprised 10 739 children (49% girls). Mothers reported their children's symptoms of depression (Short Moods and Feelings Questionnaire), anxiety (Screen for Anxiety Related Disorders), attention-deficit/hyperactivity disorder inattention and hyperactivity, oppositional-defiant disorder, conduct disorder (Parent/Teacher Rating Scale for Disruptive Behavior Disorders), and Big Five personality (short Hierarchical Personality Inventory for Children). Developmental risk factors (early gestational age and being small for gestational age) were collected from the Medical Birth Registry.

RESULTS

Goodness-of-fit indices favored a p factor model with three residual latent factors interpreted as negative affectivity, positive affectivity, and antagonism, whereas psychometric indices favored a one-factor model. ADE solutions fitted best, and regression analyses indicated a negative association between gestational age and the p factor, for both the one- and four-factor solutions.

CONCLUSION

Correlations between normative and pathological traits in middle childhood mostly reflect one heritable and psychometrically interpretable p factor, although optimal fit to data required less interpretable residual latent factors. The association between the p factor and low gestational age warrants further study of early developmental mechanisms.

Body size and brain volumetry in the rat following prolonged morphine administration in infancy and adulthood

Background

Prolonged morphine treatment in infancy is associated with a high incidence of opioid tolerance and dependence, but our knowledge of the long-term consequences of this treatment is sparse. Using a rodent model, we examined the (1) short- and (2) long-term effects of prolonged morphine administration in infancy on body weight and brain volume, and (3) we evaluated if subsequent dosing in adulthood poses an increased brain vulnerability.

Methods

Newborn rats received subcutaneous injections of either morphine or equal volume of saline twice daily for the first two weeks of life. In adulthood, animals received an additional two weeks of saline or morphine injections before undergoing structural brain MRI. After completion of treatment, structural T2-weigthed MRI images were acquired on a 7 T preclinical scanner (Bruker) using a RARE FSE sequence. Total and regional brain volumes were manually extracted from the MRI images using ITK-SNAP (v.3.6). Regions of interest included the brainstem, the cerebellum, as well as the forebrain and its components: the cerebral cortex, hippocampus, and deep gray matter (including basal ganglia, thalamus, hypothalamus, ventral tegmental area). Absolute (cm³) and normalized (as % total brain volume) values were compared using a one-way ANOVA with Tukey HSD post-hoc test.

Results

Prolonged morphine administration in infancy was associated with lower body weight and globally smaller brain volumes, which was not different between the sexes. In adulthood, females had lower body weights than males, but no difference was observed in brain volumes between treatment groups. Our results are suggestive of no long-term effect of prolonged morphine treatment in infancy with respect to body weight and brain size in either sex. Interestingly, prolonged morphine administration in adulthood was associated with smaller brain volumes that differed by sex only in case of previous exposure to morphine in infancy. Specifically, we report significantly smaller total brain volume of female rats on account of decreased volumes of forebrain and cortex.

Conclusions

Our study provides insight into the short- and long-term consequences of prolonged morphine administration in an infant rat model and suggests brain vulnerability to subsequent exposure in adulthood that might differ with sex.

Brain aging differs with cognitive ability regardless of education

Higher general cognitive ability (GCA) is associated with lower risk of neurodegenerative disorders, but neural mechanisms are unknown. GCA could be associated with more cortical tissue, from young age, i.e. brain reserve, or less cortical atrophy in adulthood, i.e. brain maintenance. Controlling for education, we investigated the relative association of GCA with reserve and maintenance of cortical volume, -area and -thickness through the adult lifespan, using multiple longitudinal cognitively healthy brain imaging cohorts (n = 3327, 7002 MRI scans, baseline age 20-88 years, followed-up for up to 11 years). There were widespread positive relationships between GCA and cortical characteristics (level-level associations). In select regions, higher baseline GCA was associated with less atrophy over time (level-change associations). Relationships remained when controlling for polygenic scores for both GCA and education. Our findings suggest that higher GCA is associated with cortical volumes by both brain reserve and -maintenance mechanisms through the adult lifespan.

Virtual Ontogeny of Cortical Growth Preceding Mental Illness

BACKGROUND

Morphology of the human cerebral cortex differs across psychiatric disorders, with neurobiology and developmental origins mostly undetermined. Deviations in the tangential growth of the cerebral cortex during pre/perinatal periods may be reflected in individual variations in cortical surface area later in life.

METHODS

Interregional profiles of group differences in surface area between cases and controls were generated using T1-weighted magnetic resonance imaging from 27,359 individuals including those with attention-deficit/hyperactivity disorder, autism spectrum disorder, bipolar disorder, major depressive disorder, schizophrenia, and high general psychopathology (through the Child Behavior Checklist). Similarity of interregional profiles of group differences in surface area and prenatal cell-specific gene expression was assessed.

RESULTS

Across the 11 cortical regions, group differences in cortical area for attention-deficit/hyperactivity disorder, schizophrenia, and Child Behavior Checklist were dominant in multimodal association cortices. The same interregional profiles were also associated with interregional profiles of (prenatal) gene expression specific to proliferative cells, namely radial glia and intermediate progenitor cells (greater expression, larger difference), as well as differentiated cells, namely excitatory neurons and endothelial and mural cells (greater expression, smaller difference). Finally, these cell types were implicated in known pre/perinatal risk factors for psychosis. Genes coexpressed with radial glia were enriched with genes implicated in congenital abnormalities, birth weight, hypoxia, and starvation. Genes coexpressed with endothelial and mural genes were enriched with genes associated with maternal hypertension and preterm birth.

CONCLUSIONS

Our findings support a neurodevelopmental model of vulnerability to mental illness whereby prenatal risk factors acting through cell-specific processes lead to deviations from typical brain development during pregnancy.

Perinatal adversities and risk of epilepsy after traumatic brain injury: A Danish nationwide cohort study

Objectives

Traumatic brain injury (TBI) and perinatal adversities such as low gestational age at birth, low birth weight, low Apgar, and being born small for gestational age are well‐established risk factors for epilepsy. We examined whether perinatal adversities modified the risk of epilepsy after TBI in a nationwide cohort study of Danish singletons born from 1982 to 2011.

Materials and Methods

We categorized perinatal adversities as a composite measure of preterm delivery, low birth weight, low Apgar score, or being born small for gestational age. Cox regression and competing risk regression were used to estimate the risk of epilepsy after TBI according to such perinatal adversities. The study included 1,715,095 singletons (51.1% males). The mean age at end of follow‐up was 19.3 years (Interquartile range [IQR] = 12.1–26.3). During follow‐up, 85,636 persons (58.2% males) sustained a TBI and 18,064 developed epilepsy (50.7% males), of whom 1329 persons had a preceding TBI.

Results

The hazard ratio (HR) of epilepsy in persons with perinatal adversities was 1.19 (95% confidence interval [CI] 1.15–1.24), compared to persons without. The HR of epilepsy in persons with TBI was 2.31 (95% CI 2.18–2.45) compared to persons without TBI, but this risk was not modified by perinatal adversities (p = 0.2460).

Conclusions

Perinatal adversities and TBI both increased the risk of epilepsy, but the risk of epilepsy after TBI was not modified by these perinatal adversities.

Altered cerebrovascular regulation in low birthweight swine

Full-term low birthweight (LBW) offspring exhibit peripheral vascular dysfunction in the postnatal period; however, whether such impairments extend to the cerebrovasculature remains to be elucidated. We used a swine model to test the hypothesis that LBW offspring would exhibit cerebrovascular dysfunction at later stages of life. Offspring from 14 sows were identified as normal birthweight (NBW) or LBW and were assessed at 28 (similar to end of infancy) and 56 (similar to childhood) days of age. LBW swine had lower absolute brain mass, but demonstrated evidence of brain sparing (increased brain mass scaled to body mass) at 56 days of age. The cerebral pulsatility index, based on transcranial Doppler, was increased in LBW swine. Moreover, arterial myography of isolated cerebral arteries revealed impaired vasoreactivity to bradykinin and reduced contribution of nitric oxide (NO) to vasorelaxation in the LBW swine. Immunoblotting demonstrated a lower ratio of phosphorylated-to-total endothelial NO synthase in LBW offspring. This impairment in NO signaling was greater at 28 vs. 56 days of age. Vasomotor responses to sodium nitroprusside (NO-donor) were unaltered, while Leu³¹, Pro³⁴ neuropeptide Y-induced vasoconstriction was enhanced in LBW swine. Increases in total Y1 receptor protein content in the LBW group were not significant. In summary, LBW offspring displayed signs of cerebrovascular dysfunction at 28 and 56 days of age, evidenced by altered cerebral hemodynamics (reflective of increased impedance) coupled with endothelial dysfunction and altered vasomotor control. Overall, the data reveal that normal variance in birthweight of full-term offspring can influence cerebrovascular function later in life.

Perinatal adversity profiles and suicide attempt in adolescence and young adulthood: longitudinal analyses from two 20-year birth cohort studies

BACKGROUND

We aimed to identify groups of children presenting distinct perinatal adversity profiles and test the association between profiles and later risk of suicide attempt.

METHODS

Data were from the Québec Longitudinal Study of Child Development (QLSCD, N = 1623), and the Avon Longitudinal Study of Parents and Children (ALSPAC, N = 5734). Exposures to 32 perinatal adversities (e.g. fetal, obstetric, psychosocial, and parental psychopathology) were modeled using latent class analysis, and associations with a self-reported suicide attempt by age 20 were investigated with logistic regression. We investigated to what extent childhood emotional and behavioral problems, victimization, and cognition explained the associations.

RESULTS

In both cohorts, we identified five profiles: No perinatal risk, Poor fetal growth, Socioeconomic adversity, Delivery complications, Parental mental health problems (ALSPAC only). Compared to children with No perinatal risk, children in the Poor fetal growth (pooled estimate QLSCD-ALSPAC, OR 1.89, 95% CI 1.04-3.44), Socioeconomic adversity (pooled-OR 1.42, 95% CI 1.08-1.85), and Parental mental health problems (OR 1.74, 95% CI 1.27-2.40), but not Delivery complications, profiles were more likely to attempt suicide. The proportion of this effect mediated by the putative mediators was larger for the Socioeconomic adversity profile compared to the others.

CONCLUSIONS

Perinatal adversities associated with suicide attempt cluster in distinct profiles. Suicide prevention may begin early in life and requires a multidisciplinary approach targeting a constellation of factors from different domains (psychiatric, obstetric, socioeconomic), rather than a single factor, to effectively reduce suicide vulnerability. The way these factors cluster together also determined the pathways leading to a suicide attempt, which can guide decision-making on personalized suicide prevention strategies.

Asphyxia at birth affects brain structure in patients on the schizophrenia-bipolar disorder spectrum and healthy participants

BACKGROUND

Uncertainty exists about what causes brain structure alterations associated with schizophrenia (SZ) and bipolar disorder (BD). Whether a history of asphyxia-related obstetric complication (ASP) - a common but harmful condition for neural tissue - contributes to variations in adult brain structure is unclear. We investigated ASP and its relationship to intracranial (ICV), global brain volumes and regional cortical and subcortical structures.

METHODS

A total of 311 patients on the SZ - BD spectrum and 218 healthy control (HC) participants underwent structural magnetic resonance imaging. They were evaluated for ASP using prospective information obtained from the Medical Birth Registry of Norway.

RESULTS

In all groups, ASP was related to smaller ICV, total brain, white and gray matter volumes and total surface area, but not to cortical thickness. Smaller cortical surface areas were found across frontal, parietal, occipital, temporal and insular regions. Smaller hippocampal, amygdala, thalamus, caudate and putamen volumes were reported for all ASP subgroups. ASP effects did not survive ICV correction, except in the caudate, which remained significantly smaller in both patient ASP subgroups, but not in the HC.

CONCLUSIONS

Since ASP was associated with smaller brain volumes in all groups, the genetic risk of developing a severe mental illness, alone, cannot easily explain the smaller ICV. Only the smaller caudate volumes of ASP patients specifically suggest that injury from ASP can be related to disease development. Our findings give support for the ICV as a marker of aberrant neurodevelopment and ASP in the etiology of brain development in BD and SZ.

Do aggregate, multimodal structural neuroimaging measures replicate regional developmental differences observed in highly cited cellular histological studies?

Influential investigations of postmortem human brain tissue showed regional differences in tissue properties at early phases of development, such as between prefrontal and primary sensory cortical regions. Large-scale neuroimaging studies enable characterization of age-related trajectories with much denser sampling of cortical regions, assessment ages, and demographic variables than postmortem tissue analyses, but no single imaging measure perfectly captures what is measured with histology. Using publicly available data from the Pediatric Imaging, Neurocognition, and Genetics (PING) study, including 951 participants with ages ranging from 3 to 21 years, we characterized cortical regional variability in developmental trajectories of multimodal brain imaging measures. Multivariate analyses integrated morphometric and microstructural cortical surface measures. To replicate foundational histological work showing delayed synapse elimination in middle frontal gyrus relative to primary sensory areas, we tested whether developmental trajectories differ between prefrontal and visual or auditory cortex. We extended this to a whole-cortex analysis of interregional differences, producing cortical parcellations with maximally different developmental trajectories. Consistent with the general conclusions of postmortem analyses, our imaging results suggest that prefrontal regions show a protracted period of greater developmental change; however, they also illustrate the challenges of drawing conclusions about the relative maturational phases of different brain regions.

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Multimodal, multivariate, nonlinear modeling, integrating morphometric and microstructural measures.

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Tested regional developmental differences previously found in highly influential cellular histological studies.

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Produced cortical parcellations with maximally different, multimodal, developmental trajectories.

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Findings converge with evidence from histological studies showing delayed prefrontal cortical development.

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Interregional differences vary by measure and illustrate complexities of defining which regions mature first.

Individual variations in 'brain age' relate to early-life factors more than to longitudinal brain change

Brain age is a widely used index for quantifying individuals’ brain health as deviation from a normative brain aging trajectory. Higher-than-expected brain age is thought partially to reflect above-average rate of brain aging. Here, we explicitly tested this assumption in two independent large test datasets (UK Biobank [main] and Lifebrain [replication]; longitudinal observations ≈ 2750 and 4200) by assessing the relationship between cross-sectional and longitudinal estimates of brain age. Brain age models were estimated in two different training datasets (n ≈ 38,000 [main] and 1800 individuals [replication]) based on brain structural features. The results showed no association between cross-sectional brain age and the rate of brain change measured longitudinally. Rather, brain age in adulthood was associated with the congenital factors of birth weight and polygenic scores of brain age, assumed to reflect a constant, lifelong influence on brain structure from early life. The results call for nuanced interpretations of cross-sectional indices of the aging brain and question their validity as markers of ongoing within-person changes of the aging brain. Longitudinal imaging data should be preferred whenever the goal is to understand individual change trajectories of brain and cognition in aging.

Scientists who study the brain and aging are keen to find an effective way to measure brain health, which could help identify people at risk for dementia or memory problems. One popular marker is ‘brain age’. This measurement uses a brain scan to estimate a person’s chronological age, then compares the estimated brain age to the person’s actual age to determine whether their brain is aging faster or slower than expected for their age.

However, since brain age relies on one brain scan taken at one point in time, it is not clear whether it really measures brain aging or if it might capture brain differences that have been present throughout the individual’s life. Studies comparing individual brain scans over several years would be necessary to know for sure.

Now, Vidal-Piñeiro et al. show that the brain-age measurement does not reflect faster brain aging. In the experiments, the researchers compared repeated brain scans of thousands of individuals over 40 years of age. The experiments showed that deviations from normative brain age detected in a single scan reflected early life differences more than changes in the brain over time. For example, people with older-looking brains were more likely to have had a low birth weight or to have a combination of genes associated with having an older looking brain.

Vidal-Piñeiro et al. show that brain age mostly reflects a pre-existing brain condition rather than brain aging. The experiments also suggest that genetics and early brain development likely have a strong impact on brain health throughout life. Future studies trying to test or develop brain-aging measurements should use serial measurements to track brain changes over time.

Towards Deciphering the Fetal Foundation of Normal Cognition and Cognitive Symptoms From Sulcation of the Cortex

Growing evidence supports that prenatal processes play an important role for cognitive ability in normal and clinical conditions. In this context, several neuroimaging studies searched for features in postnatal life that could serve as a proxy for earlier developmental events. A very interesting candidate is the sulcal, or sulco-gyral, patterns, macroscopic features of the cortex anatomy related to the fold topology-e.g., continuous vs. interrupted/broken fold, present vs. absent fold-or their spatial organization. Indeed, as opposed to quantitative features of the cortical sheet (e.g., thickness, surface area or curvature) taking decades to reach the levels measured in adult, the qualitative sulcal patterns are mainly determined before birth and stable across the lifespan. The sulcal patterns therefore offer a window on the fetal constraints on specific brain areas on cognitive abilities and clinical symptoms that manifest later in life. After a global review of the cerebral cortex sulcation, its mechanisms, its ontogenesis along with methodological issues on how to measure the sulcal patterns, we present a selection of studies illustrating that analysis of the sulcal patterns can provide information on prenatal dispositions to cognition (with a focus on cognitive control and academic abilities) and cognitive symptoms (with a focus on schizophrenia and bipolar disorders). Finally, perspectives of sulcal studies are discussed.

The association between birth weight and proxy-reported health-related quality of life among children aged 5 - 10 years old: A linked data analysis

Background

Birth weight has a substantial effect on children’s cognitive development, physical capability, and emotional development, which in turn impact on Health-Related Quality of Life (HRQoL). Generally, evidence indicates that children born with low birth weight tend to have poorer proxy-reported HRQoL, particularly at school age. However, there is limited evidence on whether variation in HRQoL exists across the entire range of possible birth weights. This study aimed to examine the association between birth weight and proxy-reported HRQoL among children aged 5–10 years old.

Methods

Data from the 1973–78 cohort of the Australian Longitudinal Study on Women’s Health were linked with state-based Perinatal Data Collections and the Mothers and their Children’s Health study for 1,589 mothers and 2,092 children aged 5 − 10 years old. Generalized estimating equations were used to model the association between birth weight and proxy-reported HRQoL measured by the Pediatric Quality of Life Inventory 4.0. Results are presented as odds ratios with 95 % confidence intervals.

Results

In this study, 15.61 % of children were at risk of impaired proxy-reported HRQoL. Each 100-gram increase in birth weight was associated with a 3 % reduction in the odds of impaired HRQoL (AOR = 0.97; 95 % CI: 0.94, 0.99). However, there was only limited evidence of an effect within the normal birth weight range (AOR = 0.97; 95 % CI: 0.94, 1.01).

Conclusions

The findings indicate that increased birth weight was protective against impaired HRQoL, although there was limited evidence of variability within the normal birth weight range. This study contributes to the existing literature by not only emphasizing the impact of low birth weight on children’s health and health-related outcomes but also by focusing on the variability within the normal birth weight range, particularly in a setting where low birth weight is less prevalent.

Contribution of birth weight to mental health, cognitive and socioeconomic outcomes: two-sample Mendelian randomisation

BACKGROUND

Low birth weight is associated with adult mental health, cognitive and socioeconomic problems. However, the causal nature of these associations remains difficult to establish owing to confounding.

AIMS

To estimate the contribution of birth weight to adult mental health, cognitive and socioeconomic outcomes using two-sample Mendelian randomisation, an instrumental variable approach strengthening causal inference.

METHOD

We used 48 independent single-nucleotide polymorphisms as genetic instruments for birth weight (genome-wide association studies' total sample: n = 264 498) and considered mental health (attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder, bipolar disorder, major depressive disorder, obsessive-compulsive disorder, post-traumatic stress disorder (PTSD), schizophrenia, suicide attempt), cognitive (intelligence) and socioeconomic (educational attainment, income, social deprivation) outcomes.

RESULTS

We found evidence for a contribution of birth weight to ADHD (OR for 1 s.d. unit decrease (~464 g) in birth weight, 1.29; 95% CI 1.03-1.62), PTSD (OR = 1.69; 95% CI 1.06-2.71) and suicide attempt (OR = 1.39; 95% CI 1.05-1.84), as well as for intelligence (β = -0.07; 95% CI -0.13 to -0.02) and socioeconomic outcomes, i.e. educational attainment (β = -0.05; 95% CI -0.09 to -0.01), income (β = -0.08; 95% CI -0.15 to -0.02) and social deprivation (β = 0.08; 95% CI 0.03-0.13). However, no evidence was found for a contribution of birth weight to the other examined mental health outcomes. Results were consistent across a wide range of sensitivity analyses.

CONCLUSIONS

These findings support the hypothesis that birth weight could be an important element on the causal pathway to mental health, cognitive and socioeconomic outcomes.

Birth weight is associated with brain tissue volumes seven decades later but not with MRI markers of brain ageing

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Larger birth weight is associated with larger brain tissue volumes at age 73.

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Birth weight is not associated with age-associated brain features.

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Effect of birth weight on brain volumes is independent of overall body size.

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Early life growth is likely to confer brain tissue reserve in later life.

Birth weight, an indicator of fetal growth, is associated with cognitive outcomes in early life (which are predictive of cognitive ability in later life) and risk of metabolic and cardiovascular disease across the life course. Brain health in older age, indexed by MRI features, is associated with cognitive performance, but little is known about how variation in normal birth weight impacts on brain structure in later life. In a community dwelling cohort of participants in their early seventies we tested the hypothesis that birth weight is associated with the following MRI features: total brain (TB), grey matter (GM) and normal appearing white matter (NAWM) volumes; whiter matter hyperintensity (WMH) volume; a general factor of fractional anisotropy (gFA) and peak width skeletonised mean diffusivity (PSMD) across the white matter skeleton. We also investigated the associations of birth weight with cortical surface area, volume and thickness. Birth weight was positively associated with TB, GM and NAWM volumes in later life (β ≥ 0.194), and with regional cortical surface area but not gFA, PSMD, WMH volume, or cortical volume or thickness. These positive relationships appear to be explained by larger intracranial volume, rather than by age-related tissue atrophy, and are independent of body height and weight in adulthood. This suggests that larger birth weight is linked to more brain tissue reserve in older life, rather than age-related brain structural features, such as tissue atrophy or WMH volume.

Neonatal amygdala microstructure mediates the relationship between gestational glycemia and offspring adiposity

INTRODUCTION

To determine if variations in the neonatal amygdala mediate the association between maternal antenatal glycemia and offspring adiposity in early childhood.

RESEARCH DESIGN AND METHODS

123 non-obese pregnant women with no pregnancy complications aside from gestational diabetes underwent a 75 g 2-hour oral glucose tolerance test at 26-28 weeks' gestation. Volume and fractional anisotropy (FA) of the neonatal amygdala (5-17 days old) were measured by MRI. The Body Mass Index (BMI) z-scores and sum of skinfold thickness (subscapular and triceps) of these children were tracked up to 60 months of age (18, 24, 36, 48, 54 and 60 months).

RESULTS

Maternal fasting glucose levels were positively associated with the offspring's sum of skinfold thickness at age 48 months (β=3.12, 95% CI 0.18 to 6.06 mm) and 60 months (β=4.14, 95% CI 0.46 to 7.82 mm) and BMI z-scores at 48 months (β=0.94, 95% CI 0.03 to 1.85), 54 months (β=0.74, 95% CI 0.12 to 1.36) and 60 months (β=0.74, 95% CI 0.08 to 1.39). Maternal fasting glucose was negatively associated with the offspring's FA of the right amygdala (β=-0.019, 95% CI -0.036 to -0.003). Right amygdala FA was negatively associated with the sum of skinfold thickness in the offspring at age 48 months (β=-56.95, 95% CI -98.43 to -15.47 mm), 54 months (β=-46.18, 95% CI -88.57 to -3.78 mm), and 60 months (β=-53.69, 95% CI -105.74 to -1.64 mm). The effect sizes mediated by right amygdala FA between fasting glucose and sum of skinfolds were estimated at β=5.14 (95% CI 0.74 to 9.53) mm (p=0.022), β=4.40 (95% CI 0.08 to 8.72) (p=0.049) mm and β=4.56 (95% CI -0.17 to 9.29) mm (p=0.059) at 48, 54 and 60 months, respectively.

CONCLUSIONS

In the offspring of non-obese mothers, gestational fasting glucose concentration is negatively associated with neonatal right amygdala FA and positively associated with childhood adiposity. Neonatal right amygdala FA may be a potential mediator between maternal glycemia and childhood adiposity.

Linked patterns of biological and environmental covariation with brain structure in adolescence: a population-based longitudinal study

Adolescence is a period of major brain reorganization shaped by biologically timed and by environmental factors. We sought to discover linked patterns of covariation between brain structural development and a wide array of these factors by leveraging data from the IMAGEN study, a longitudinal population-based cohort of adolescents. Brain structural measures and a comprehensive array of non-imaging features (relating to demographic, anthropometric, and psychosocial characteristics) were available on 1476 IMAGEN participants aged 14 years and from a subsample reassessed at age 19 years (n = 714). We applied sparse canonical correlation analyses (sCCA) to the cross-sectional and longitudinal data to extract modes with maximum covariation between neuroimaging and non-imaging measures. Separate sCCAs for cortical thickness, cortical surface area and subcortical volumes confirmed that each imaging phenotype was correlated with non-imaging features (sCCA r range: 0.30-0.65, all P_FDR < 0.001). Total intracranial volume and global measures of cortical thickness and surface area had the highest canonical cross-loadings (|ρ| = 0.31-0.61). Age, physical growth and sex had the highest association with adolescent brain structure (|ρ| = 0.24-0.62); at baseline, further significant positive associations were noted for cognitive measures while negative associations were observed at both time points for prenatal parental smoking, life events, and negative affect and substance use in youth (|ρ| = 0.10-0.23). Sex, physical growth and age are the dominant influences on adolescent brain development. We highlight the persistent negative influences of prenatal parental smoking and youth substance use as they are modifiable and of relevance for public health initiatives.

Cellular correlates of cortical thinning throughout the lifespan

Cortical thinning occurs throughout the entire life and extends to late-life neurodegeneration, yet the neurobiological substrates are poorly understood. Here, we used a virtual-histology technique and gene expression data from the Allen Human Brain Atlas to compare the regional profiles of longitudinal cortical thinning through life (4004 magnetic resonance images [MRIs]) with those of gene expression for several neuronal and non-neuronal cell types. The results were replicated in three independent datasets. We found that inter-regional profiles of cortical thinning related to expression profiles for marker genes of CA1 pyramidal cells, astrocytes and, microglia during development and in aging. During the two stages of life, the relationships went in opposite directions: greater gene expression related to less thinning in development and vice versa in aging. The association between cortical thinning and cell-specific gene expression was also present in mild cognitive impairment and Alzheimer's Disease. These findings suggest a role of astrocytes and microglia in promoting and supporting neuronal growth and dendritic structures through life that affects cortical thickness during development, aging, and neurodegeneration. Overall, the findings contribute to our understanding of the neurobiology underlying variations in MRI-derived estimates of cortical thinning through life and late-life disease.

Shared Neural Substrates Underlying Reading and Visual Matching: A Longitudinal Investigation

The role of visual skills in reading acquisition has long been debated and whether there is shared neurobiological basis between visual skills and reading is not clear. This study investigated the relationship between Visual Matching and reading and their shared neuroanatomical basis. Two hundred and ninety-three typically developing Mandarin-speaking children were followed in a longitudinal study from ages 4 to 11 years old. A subsample of 79 children was further followed up at 14 years old when the MRI data were collected. Results showed that the development of Visual Matching from ages 6 to 8 predicted reading accuracy at age 11. In addition, both the development of Visual Matching and reading accuracy were associated with cortical surface area of a cluster located in fusiform gyrus. These findings suggested that the mapping from visual codes to phonological codes is important in learning to read and that left fusiform gyrus provided neural basis for such mapping. Implications of these findings in light of a new approach toward the neurocognitive mechanisms underlying reading development are discussed.

Continuity and Discontinuity in Human Cortical Development and Change From Embryonic Stages to Old Age

The human cerebral cortex is highly regionalized, and this feature emerges from morphometric gradients in the cerebral vesicles during embryonic development. We tested if this principle of regionalization could be traced from the embryonic development to the human life span. Data-driven fuzzy clustering was used to identify regions of coordinated longitudinal development of cortical surface area (SA) and thickness (CT) (n = 301, 4-12 years). The principal divide for the developmental SA clusters extended from the inferior-posterior to the superior-anterior cortex, corresponding to the major embryonic morphometric anterior-posterior (AP) gradient. Embryonic factors showing a clear AP gradient were identified, and we found significant differences in gene expression of these factors between the anterior and posterior clusters. Further, each identified developmental SA and CT clusters showed distinguishable life span trajectories in a larger longitudinal dataset (4-88 years, 1633 observations), and the SA and CT clusters showed differential relationships to cognitive functions. This means that regions that developed together in childhood also changed together throughout life, demonstrating continuity in regionalization of cortical changes. The AP divide in SA development also characterized genetic patterning obtained in an adult twin sample. In conclusion, the development of cortical regionalization is a continuous process from the embryonic stage throughout life.

Effects of maternal stress and nutrient restriction during gestation on offspring neuroanatomy in humans

Cognitive and mental health are major determinants of quality of life, allowing integration into society at all ages. Human epidemiological and animal studies indicate that in addition to genetic factors and lifestyle, prenatal environmental influences may program neuropsychiatric disorders in later life. While several human studies have examined the effects of prenatal stress and nutrient restriction on brain function and mental health in later life, potentially mediating effects of prenatal stress and nutrient restriction on offspring neuroanatomy in humans have been studied only in recent years. Based on neuroimaging and anatomical data, we comprehensively review the studies in this emerging field. We relate prenatal environmental influences to neuroanatomical abnormalities in the offspring, measured in utero and throughout life. We also assess the relationship between neuroanatomical abnormalities and cognitive and mental disorders. Timing- and gender-specific effects are considered, if reported. Our review provides evidence for adverse effects of an unfavorable prenatal environment on structural brain development that may contribute to the risk for cognitive, behavioral and mental health problems throughout life.

Genetic risk for Alzheimer disease predicts hippocampal volume through the human lifespan

Objective

To test the hypothesis that genetic risk for Alzheimer disease (AD) may represent a stable influence on the brain from early in life, rather than being primarily age dependent, we investigated in a lifespan sample of 1,181 persons with a total of 2,690 brain scans, whether higher polygenic risk score (PGS) for AD and presence of APOE ε4 was associated with lower hippocampal volumes to begin with, as an offset effect, or possibly faster decline in older age.

Methods

Using general additive mixed models, we assessed the relations of PGS for AD, including variants in APOE with hippocampal volume and its change in a cognitively healthy longitudinal lifespan sample (age range: 4–95 years, mean visit age 39.7 years, SD 26.9 years), followed for up to 11 years.

Results

AD-PGS and APOE ε4 in isolation showed a significant negative effect on hippocampal volume. The effect of a 1 sample SD increase in AD-PGS on hippocampal volume was estimated to –36.4 mm³ (confidence interval [CI]: –71.8, –1.04) and the effect of carrying ε4 allele(s) –107.0 mm³ (CI: –182.0, –31.5). Offset effects of AD-PGS and APOE ε4 were present in hippocampal development, and interactions between age and genetic risk on volume change were not consistently observed.

Conclusions

Endophenotypic manifestation of polygenic risk for AD may be seen across the lifespan in cognitively healthy persons, not being confined to clinical populations or older age. This emphasizes that a broader population and age range may be relevant targets for attempts to prevent AD.

Birth weight is associated with adolescent brain development: A multimodal imaging study in monozygotic twins

Previous research has shown that the prenatal environment, commonly indexed by birth weight (BW), is a predictor of morphological brain development. We previously showed in monozygotic (MZ) twins associations between BW and brain morphology that were independent of genetics. In the present study, we employed a longitudinal MZ twin design to investigate whether variations in prenatal environment (as indexed by discordance in BW) are associated with resting‐state functional connectivity (rs‐FC) and with structural connectivity. We focused on the limbic and default mode networks (DMNs), which are key regions for emotion regulation and internally generated thoughts, respectively. One hundred and six healthy adolescent MZ twins (53 pairs; 42% male pairs) followed longitudinally from birth underwent a magnetic resonance imaging session at age 15. Graph theoretical analysis was applied to rs‐FC measures. TrackVis was used to determine track count as an indicator of structural connectivity strength. Lower BW twins had less efficient limbic network connectivity as compared to their higher BW co‐twin, driven by differences in the efficiency of the right hippocampus and right amygdala. Lower BW male twins had fewer tracks connecting the right hippocampus and right amygdala as compared to their higher BW male co‐twin. There were no associations between BW and the DMN. These findings highlight the possible role of unique prenatal environmental influences in the later development of efficient spontaneous limbic network connections within healthy individuals, irrespective of DNA sequence or shared environment.

Evaluating the effect of birth weight on brain volumes and depression: An observational and genetic study using UK Biobank cohort

Background.

Birth weight influences not only brain development, but also mental health outcomes, including depression, but the underlying mechanism is unclear.

Methods.

The phenotypic data of 12,872–91,009 participants (59.18–63.38% women) from UK Biobank were included to test the associations between the birth weight, depression, and brain volumes through the linear and logistic regression models. As birth weight is highly heritable, the polygenic risk scores (PRSs) of birth weight were calculated from the UK Biobank cohort (154,539 participants, 56.90% women) to estimate the effect of birth weight-related genetic variation on the development of depression and brain volumes. Finally, the mediation analyses of step approach and mediation analysis were used to estimate the role of brain volumes in the association between birth weight and depression. All analyses were conducted sex stratified to assess sex-specific role in the associations.

Result.

We observed associations between birth weight and depression (odds ratio [OR] = 0.968, 95% confidence interval [CI] = 0.957–0.979, p = 2.29 × 10⁻⁶). Positive associations were observed between birth weight and brain volumes, such as gray matter (B = 0.131, p = 3.51 × 10⁻⁷⁴) and white matter (B = 0.129, p = 1.67 × 10⁻⁷⁴). Depression was also associated with brain volume, such as left thalamus (OR = 0.891, 95% CI = 0.850–0.933, p = 4.46 × 10⁻⁵) and right thalamus (OR = 0.884, 95% CI = 0.841–0.928, p = 2.67 × 10⁻⁵). Additionally, significant mediation effects of brain volume were found for the associations between birth weight and depression through steps approach and mediation analysis, such as gray matter (B = –0.220, p = 0.020) and right thalamus (B = –0.207, p = 0.014).

Conclusions.

Our results showed the associations among birth weight, depression, and brain volumes, and the mediation effect of brain volumes also provide evidence for the sex-specific of associations.

Early environmental risk factors for neurodevelopmental disorders - a systematic review of twin and sibling studies

While neurodevelopmental disorders (NDDs) are highly heritable, several environmental risk factors have also been suggested. However, the role of familial confounding is unclear. To shed more light on this, we reviewed the evidence from twin and sibling studies. A systematic review was performed on case control and cohort studies including a twin or sibling within-pair comparison of neurodevelopmental outcomes, with environmental exposures until the sixth birthday. From 7,315 screened abstracts, 140 eligible articles were identified. After adjustment for familial confounding advanced paternal age, low birth weight, birth defects, and perinatal hypoxia and respiratory stress were associated with autism spectrum disorder (ASD), and low birth weight, gestational age and family income were associated with attention-deficit/hyperactivity disorder (ADHD), categorically and dimensionally. Several previously suspected factors, including pregnancy-related factors, were deemed due to familial confounding. Most studies were conducted in North America and Scandinavia, pointing to a global research bias. Moreover, most studies focused on ASD and ADHD. This genetically informed review showed evidence for a range of environmental factors of potential casual significance in NDDs, but also points to a critical need of more genetically informed studies of good quality in the quest of the environmental causes of NDDs.

Patterns of sociocognitive stratification and perinatal risk in the child brain

The expanding behavioral repertoire of the developing brain during childhood and adolescence is shaped by complex brain-environment interactions and flavored by unique life experiences. The transition into young adulthood offers opportunities for adaptation and growth but also increased susceptibility to environmental perturbations, such as the characteristics of social relationships, family environment, quality of schools and activities, financial security, urbanization and pollution, drugs, cultural practices, and values, that all act in concert with our genetic architecture and biology. Our multivariate brain-behavior mapping in 7,577 children aged 9 to 11 y across 585 brain imaging phenotypes and 617 cognitive, behavioral, psychosocial, and socioeconomic measures revealed three population modes of brain covariation, which were robust as assessed by cross-validation and permutation testing, taking into account siblings and twins, identified using genetic data. The first mode revealed traces of perinatal complications, including preterm and twin birth, eclampsia and toxemia, shorter period of breastfeeding, and lower cognitive scores, with higher cortical thickness and lower cortical areas and volumes. The second mode reflected a pattern of sociocognitive stratification, linking lower cognitive ability and socioeconomic status to lower cortical thickness, area, and volumes. The third mode captured a pattern related to urbanicity, with particulate matter pollution (PM²⁵) inversely related to home value, walkability, and population density, associated with diffusion properties of white matter tracts. These results underscore the importance of a multidimensional and interdisciplinary understanding, integrating social, psychological, and biological sciences, to map the constituents of healthy development and to identify factors that may precede maladjustment and mental illness.

Environmental Influences on Infant Cortical Thickness and Surface Area

Cortical thickness (CT) and surface area (SA) vary widely between individuals and are associated with intellectual ability and risk for various psychiatric and neurodevelopmental conditions. Factors influencing this variability remain poorly understood, but the radial unit hypothesis, as well as the more recent supragranular cortex expansion hypothesis, suggests that prenatal and perinatal influences may be particularly important. In this report, we examine the impact of 17 major demographic and obstetric history variables on interindividual variation in CT and SA in a unique sample of 805 neonates who received MRI scans of the brain around 2 weeks of age. Birth weight, postnatal age at MRI, gestational age at birth, and sex emerged as important predictors of SA. Postnatal age at MRI, paternal education, and maternal ethnicity emerged as important predictors of CT. These findings suggest that individual variation in infant CT and SA is explained by different sets of environmental factors with neonatal SA more strongly influenced by sex and obstetric history and CT more strongly influenced by socioeconomic and ethnic disparities. Findings raise the possibility that interventions aimed at reducing disparities and improving obstetric outcomes may alter prenatal/perinatal cortical development.

Brain status modeling with non-negative projective dictionary learning

Accurate prediction of individuals' brain age is critical to establish a baseline for normal brain development. This study proposes to model brain development with a novel non-negative projective dictionary learning (NPDL) approach, which learns a discriminative representation of multi-modal neuroimaging data for predicting brain age. Our approach encodes the variability of subjects in different age groups using separate dictionaries, projecting features into a low-dimensional manifold such that information is preserved only for the corresponding age group. The proposed framework improves upon previous discriminative dictionary learning methods by incorporating orthogonality and non-negativity constraints, which remove representation redundancy and perform implicit feature selection. We study brain development on multi-modal brain imaging data from the PING dataset (N = 841, age = 3-21 years). The proposed analysis uses our NDPL framework to predict the age of subjects based on cortical measures from T1-weighted MRI and connectome from diffusion weighted imaging (DWI). We also investigate the association between age prediction and cognition, and study the influence of gender on prediction accuracy. Experimental results demonstrate the usefulness of NDPL for modeling brain development.

Functional connectivity of the reading network is associated with prenatal polybrominated diphenyl ether concentrations in a community sample of 5 year-old children: A preliminary study

Genetic factors explain 60 percent of variance in reading disorder. Exposure to neurotoxicants, including polybrominated diphenyl ethers (PBDEs), may be overlooked risk factors for reading problems. We used resting-state functional magnetic resonance imaging (rs-fMRI) to examine associations between prenatal PBDE concentrations and functional connectivity of a reading-related network (RN) in a community sample of 5-year-old children (N = 33). Maternal serum PBDE concentrations (∑PBDE) were measured at 12.2 ± 2.8 weeks gestation (mean ± SD). The RN was defined by 12 regions identified in prior task-based fMRI meta-analyses; global efficiency (GE) was used to measure network integration. Linear regression evaluated associations between ∑PBDE, word reading, and GE of the RN and the default mode network (DMN); the latter to establish specificity of findings. Weighted quantile sum regression analyses evaluated the contributions of specific PBDE congeners to observed associations. Greater RN efficiency was associated with better word reading in these novice readers. Children with higher ∑PBDE showed reduced GE of the RN; ∑PBDE was not associated with DMN efficiency, demonstrating specificity of our results. Consistent with prior findings, ∑PBDE was not associated word reading at 5-years-old. Altered efficiency and integration of the RN may underlie associations between ∑PBDE concentrations and reading problems observed previously in older children.

The Relationship between Pesticide Exposure and Umbilical Serum IGF-1 Levels and Low-birth Weight: A Case-control Study in Brebes, Indonesia

BACKGROUND

Birth weight is very important for long-term physical, mental, health, and brain development. Pesticide exposure is thought to interfere with fetal growth, among others, through disruption of the function of the insulin-like growth hormone-1 (IGF-1) hormone.

OBJECTIVE

To analyze the relationship between exposure to pesticides during pregnancy and low-birth weight (LBW) through the disruption of the IGF-1 hormone.

METHODS

In a case-control study, babies born with LBW (birth weight <2500 g) and those born later with normal birth weight (=2500 g) at 2 hospitals in Brebes were chosen as cases and controls, respectively. Maternal pesticide exposure was measured by interview using a questionnaire. Umbilical serum IGF-I level was tested using the ELISA method.

RESULTS

There was a significant relationship between pesticide exposure during pregnancy and LBW (OR 6.8; 95% CI 2.0 to 22.9) and low umbilical serum IGF-1 levels (OR 3.6; 95% CI 1.2 to 11.1). There was a significant relationship between low umbilical serum IGF-1 levels and LBW (OR 8.9; 95% CI 2.4 to 32.1).

CONCLUSION

There was a significant relationship between pesticide exposure during pregnancy and LBW through the umbilical serum IGF-1 reduction pathway.

Determining the effect of folate diets during pregnancy and lactation on neurobehavioural changes in the adult life of offspring

OBJECTIVES

Animal and human studies have demonstrated that folic acid (FA) is essential for nervous system and brain development. In humans, insufficient maternal FA intake is known to cause neural tube defects, autism spectrum, and other neurodevelopmental disorders in children. The present study aimed to determine the impact of maternal FA supplementation on psychomotor skills and learning and memory functions in their adult offspring.

METHODS

Eighteen female Wistar rats were randomly divided into three groups. The animals were fed three different concentrations of FA from preconception to pregnancy and during lactation. The adult offspring were assessed for neurobehavioural changes and histological confirmation by hippocampal neuron quantification.

RESULTS

Neurobehavioural assessment revealed a significantly smaller number of alternations, a higher percentage bias, and a greater number of working and reference memory errors. The increased time spent in the dark compartment in the FA-supplementation group indicated deficit(s) in learning memory. Hippocampal neuron quantification revealed a higher mean number of viable neurons in the cornu ammonis (CA) region in the control group (CA1 region, 31.2 ± 3.2; CA3 region, 23.2 ± 3.2), with a distinct nucleus in both regions, and least in the FA-supplementation group (CA1 region, 24.2 ± 3.1; CA3 region, 15.2 ± 2.2).

CONCLUSION

Results of this investigation support the possible negative effect of high levels of maternal FA supplementation during pregnancy and lactation. Such alterations potentially lead to neurobehavioural changes in the adult offspring of Wistar rats.

Early life factors, gray matter brain volume and academic performance in overweight/obese children: The ActiveBrains project

Early life factors may influence brain and academic outcomes later in life, especially during childhood. Here we investigate the associations of early life factors (i.e., birth weight, birth length, and breastfeeding) with gray matter volume, adjusted for body mass index and cardiorespiratory fitness, and ii) we test whether early-life factor-related differences in gray matter volume are associated with academic performance in overweight/obese children. 96 children with overweight/obesity aged 8-11 years participated. Birth weight, birth length and gestational age were collected from birth records, and breastfeeding practices were asked to parents. T1-weighted images were acquired with a 3.0 T Magnetom Tim Trio system. Academic performance was assessed with the Bateria III Woodcock-Muñoz Tests of Achievement. Whole-brain voxel-wise multiple regressions were used to test the associations of each early life factor with gray matter volume. Higher birth weight and birth length were associated with greater gray matter volume in 9 brain regions including the middle frontal gyrus, rectal gyrus, thalamus, putamen, middle temporal gyrus, lingual gyrus, middle occipital gyrus, calcarine cortex and cerebellum bilaterally (β ranging from 0.361 to 0.539, t ranging from 3.46 to 5.62 and cluster size from 82 to 4478 voxels; p < 0.001); and greater duration of any breastfeeding was associated with greater gray matter volume in 3 regions including the bilateral inferior frontal gyrus and rolandic operculum (β ranging from 0.359 to 0.408, t ranging from 4.01 to 4.32 and cluster size from 64 to 171 voxels; p < 0.001). No associations were found for duration of exclusive breastfeeding. Additionally, none of the gray matter regions that were associated with the early life factors were associated with academic performance (all p > 0.05). Our results demonstrate that birth weight, birth length, and breastfeeding are predictive of gray matter volume of numerous brain structures that are involved in higher order cognition and emotion regulation, but how these results relate to measures of academic achievement remain a matter of speculation.

Impact of Polygenic Risk for Schizophrenia on Cortical Structure in UK Biobank

BACKGROUND

Schizophrenia is a neurodevelopmental disorder with many genetic variants of individually small effect contributing to phenotypic variation. Lower cortical thickness (CT), surface area, and cortical volume have been demonstrated in people with schizophrenia. Furthermore, a range of obstetric complications (e.g., lower birth weight) are consistently associated with an increased risk for schizophrenia. We investigated whether a high polygenic risk score for schizophrenia (PGRS-SCZ) is associated with CT, surface area, and cortical volume in UK Biobank, a population-based sample, and tested for interactions with birth weight.

METHODS

Data were available for 2864 participants (n_male/n_female = 1382/1482; mean age = 62.35 years, SD = 7.40). Linear mixed models were used to test for associations among PGRS-SCZ and cortical volume, surface area, and CT and between PGRS-SCZ and birth weight. Interaction effects of these variables on cortical structure were also tested.

RESULTS

We found a significant negative association between PGRS-SCZ and global CT; a higher PGRS-SCZ was associated with lower CT across the whole brain. We also report a significant negative association between PGRS-SCZ and insular lobe CT. PGRS-SCZ was not associated with birth weight and no PGRS-SCZ × birth weight interactions were found.

CONCLUSIONS

These results suggest that individual differences in CT are partly influenced by genetic variants and are most likely not due to factors downstream of disease onset. This approach may help to elucidate the genetic pathophysiology of schizophrenia. Further investigation in case-control and high-risk samples could help identify any localized effects of PGRS-SCZ, and other potential schizophrenia risk factors, on CT as symptoms develop.

Impact of a prenatal episode and diagnosis in women with serious mental illnesses on neonatal complications (prematurity, low birth weight, and hospitalization in neonatal intensive care units)

Pregnancy in women with mental disorders is increasingly common. The aim of this study was to determine, in women with severe mental illnesses, whether a prenatal episode was related to neonatal complications and if a specific disorder was associated with a higher risk. A population of infants and their mothers (n = 1439) jointly admitted to psychiatric Mother-Baby Units in France and Belgium (2001-2010) was assessed respectively for prematurity, low birth weight (LBW), hospitalization in neonatal intensive care units (NICUs), and maternal mental health during pregnancy. Logistic regression was used to explore the association between neonatal complications and a prenatal episode of mental illness and if the presence of a specific disorder was related to a higher risk, taking into account maternal socio-demographic characteristics, pregnancy data, and antenatal exposure to psychotropic drugs. Among the children, 145 (10.2%) were premature, 226 (15.8%) had a LBW, and 348 (24.3%) have been hospitalized in neonatology. The presence of an episode of mental illness during pregnancy was linked to LBW (OR = 2.21 [1.44-3.38]; p = 0.003) and NICU hospitalizations (OR = 1.53 [1.06-2.19], p = 0.002). Among diagnoses, the presence of a severe substance use disorder in these women was related to LBW (OR = 2.96 [1.49-5.85]; p = 0.002) and NICU (OR = 2.88 [1.56-5.29]; p = 0.04). Our results underline the importance of systematic and early detection of psychiatric symptoms and substance use disorders during pregnancy in preventing neonatal complications in women with serious mental illness.

Cortical abnormalities in youth at clinical high-risk for psychosis: Findings from the NAPLS2 cohort

In a recent machine learning study classifying “brain age” based on cross-sectional neuroanatomical data, clinical high-risk (CHR) individuals were observed to show deviation from the normal neuromaturational pattern, which in turn was predictive of greater risk of conversion to psychosis and a pattern of stably poor functional outcome. These effects were unique to cases who were between 12 and 17 years of age when their prodromal and psychotic symptoms began, suggesting that neuroanatomical deviance observable at the point of ascertainment of a CHR syndrome marks risk for an early onset form of psychosis. In the present study, we sought to clarify the pattern of neuroanatomical deviance linked to this “early onset” form of psychosis and whether this deviance is associated with poorer premorbid functioning. T₁ MRI scans from 378 CHR individuals and 190 healthy controls (HC) from the North American Prodrome Longitudinal Study (NAPLS2) were analyzed. Widespread smaller cortical volume was observed among CHR individuals compared with HC at baseline evaluation, particularly among the younger group (i.e., those who were 12 to 17 years of age). Moreover, the younger CHR individuals who converted or presented worsened clinical symptoms at follow-up (within 2 years) exhibited smaller surface area in rostral anterior cingulate, lateral and medial prefrontal regions, and parahippocampal gyrus relative to the younger CHR individuals who remitted or presented a stable pattern of prodromal symptoms at follow-up. In turn, poorer premorbid functioning in childhood was associated with smaller surface area in medial orbitofrontal, lateral frontal, rostral anterior cingulate, precuneus, and temporal regions. Together with our prior report, these results are consistent with the view that neuroanatomical deviance manifesting in early adolescence marks vulnerability to a form of psychosis presenting with poor premorbid adjustment, an earlier age of onset (generally prior to the age of 18 years), and poor long-term outcome.

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Widespread cortical deficiencies observed in CHR individuals in early adolescence.

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Steeper rate of cortical thinning among converters in late adolescence.

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Neuroanatomical deviance in CHR youth is associated with clinical outcome.

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CHR individuals with poorer premorbid functioning exhibited reduced surface area.

Associations of gestational age and birth anthropometric indicators with brain white matter maturation in full-term neonates

Newborn assessments, including gestational age (GA) and anthropometric measurements (birth weight, crown-heel length, head circumference) are routinely performed in pediatric settings, being used as important indicators in assessing neonatal development. Close associations of these birth indicators with later cognitive abilities were also reported. However, specific associations of these indicators with white matter (WM) development during the neonatal period remain unclear, as well as the extent to which they influence WM maturation. To address this issue, 51 full-term neonates (GA range, 37-42 weeks) with no abnormalities on MRI were retrospectively recruited. Specific correlations between birth indicators and WM maturation, quantified by diffusion tensor imaging (DTI)-metrics (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity), were identified by using DTI tract-based spatial statistics and automated fiber-tract quantification. Our findings suggest that (a) higher GA, birth weight, and crown-heel length may indicate greater WM maturation in full-term neonates, while head circumference presented weak correlation with WM maturation during early newborn period; (b) among the four indicators examined, GA was the one most associated with WM maturation. We believe that this study advances our knowledge of specific correlations between birth indicators and neonatal brain development and provides a valuable reference for future neonatal studies.

Association of Fetal Growth With General and Specific Mental Health Conditions

IMPORTANCE

It is unclear if the associations between fetal growth and later mental health conditions remain after controlling for familial factors and psychiatric comorbidity.

OBJECTIVE

To examine the associations between fetal growth and general and specific mental health conditions, controlling for familial factors.

DESIGN, SETTING, AND PARTICIPANTS

This register-based study conducted in Sweden analyzed 546 894 pairs of full siblings born between January 1, 1973, and December 31, 1998. Sibling pairs were followed up through December 31, 2013. First, population-based and within-sibling pair associations (which controlled for time-invariant familial confounders) between fetal growth and the outcomes were estimated. Second, exploratory factor analysis was applied to the outcomes to derive 1 general factor and 4 specific and independent factors. Third, the general and specific factors were regressed on fetal growth. Statistical analysis was performed from March 27, 2017, to October 27, 2018.

MAIN OUTCOME AND MEASURES

The outcomes were 11 psychiatric diagnoses (depression, anxiety, obsessive-compulsive disorder, posttraumatic stress disorder, bipolar disorder, alcohol abuse, drug use, attention-deficit/hyperactivity disorder, autism, schizophrenia, and schizoaffective disorder) and court convictions of violent crimes. Birth weight (in kilograms) statistically adjusted for gestational age was the exposure.

RESULTS

The mean (SD) age of the 1 093 788 participants was 27.2 (6.8) years (range, 15.1-40.9 years) and 51.5% were male. Nine outcomes were significantly associated with birth weight in the population at large: depression (odds ratio [OR], 0.96; 95% CI, 0.95-0.98), anxiety (OR, 0.94; 95% CI, 0.92-0.95), posttraumatic stress disorder (OR, 0.91; 95% CI, 0.89-0.93), bipolar disorder (OR, 0.94; 95% CI, 0.89-1.00), alcohol abuse (OR, 0.89; 95% CI, 0.87-0.91), drug use (OR, 0.83; 95% CI, 0.80-0.85), violent crimes (OR, 0.85; 95% CI, 0.83-0.86), attention-deficit/hyperactivity disorder (OR, 0.88; 95% CI, 0.86-0.90), and autism (OR, 0.95; 95% CI, 0.92-0.97). Only depression (OR, 0.95; 95% CI 0.92-0.98), obsessive-compulsive disorder (OR, 0.93; 95% CI, 0.87-0.99), attention-deficit/hyperactivity disorder (OR, 0.86; 95% CI, 0.82-0.89), and autism (OR, 0.72; 95% CI, 0.69-0.76) remained significantly associated within sibling pairs. An exploratory factor analysis indicated that 1 general and 4 specific factors (capturing anxiety, externalizing, neurodevelopmental, and psychotic conditions) fit the outcomes well. Across almost all sensitivity analyses, an increase in birth weight by 1 kg significantly reduced the general (β, -0.047; 95% CI, -0.071 to -0.023) and the specific neurodevelopmental factors (β, -0.159; 95% CI, -0.190 to -0.128) within sibling pairs.

CONCLUSIONS AND RELEVANCE

Controlling for familial confounders, reduced fetal growth was associated with a small but significant increase in the general factor of psychopathology and a moderate increase in a specific neurodevelopmental factor.

Fluid Reasoning Mediates the Association of Birth Weight With ADHD Symptoms in Youth From Multiplex Families With ADHD

OBJECTIVE

We tested mediation of birth weight and ADHD symptoms by multiple biologically plausible neurocognitive functions and evaluated familiality of observed indirect effects.

METHOD

647 youth from 284 multiplex families with ADHD completed the Arithmetic, Digit Span, Vocabulary, and Block Design subtests of the Wechsler Intelligence Scale for Children (WISC). Multiple mediation tested WISC subtests as mediators of birth weight and multi-informant ADHD symptoms. Familiality of indirect effects was estimated via moderated mediation comparing conditional indirect effects across siblings concordant and discordant for ADHD.

RESULTS

Controlling for IQ and demographic factors, Arithmetic uniquely mediated birth weight and ADHD symptoms. Conditional indirect effects through Arithmetic did not differ across ADHD concordant and discordant siblings.

CONCLUSION

These cross-sectional findings support previous prospective longitudinal research implicating Arithmetic (i.e., fluid reasoning) as a preliminary causal mediator of birth weight and ADHD symptoms, and suggest that this pathway is independent of genetic influences on ADHD.

What are the earlier life contributions to reserve and resilience?

The brain's structures and functions arise from a combination of developmental processes and interaction with environmental experiences, beginning in utero and continuing throughout the lifespan. Broadly, the process that we think of as "successful aging" likely has its foundation in early life and is continuously shaped as life experiences are programmed into the brain in response to a changing environment. Thus, individual lifestyle choices and interventions aimed at increasing cognitive reserve and resilience could change the course of cognitive aging. To determine the relative efficacy of these approaches, we will need to understand how the timing of these interventions (e.g., age, duration, frequency) influences cognitive capacity through the lifespan. Although analysis of age-related changes in cognitive function reveals a general decline at the population level, it has become clear that there is great individual variance in the extent to which cognitive function changes with advanced age. The factors responsible for the individual differences in cognitive decline are unclear, but uncovering them with new analytical tools, epigenetic approaches, and subpopulation studies will provide a roadmap toward enhancing reserve and resilience in the population at large and preserving cognitive function in a greater number of aging individuals.

Decreased event-related theta power and phase-synchrony in young binge drinkers during target detection: An anatomically-constrained MEG approach

BACKGROUND

The prevalence of binge drinking has risen in recent years. It is associated with a range of neurocognitive deficits among adolescents and young emerging adults who are especially vulnerable to alcohol use. Attention is an essential dimension of executive functioning and attentional disturbances may be associated with hazardous drinking. The aim of the study was to examine the oscillatory neural dynamics of attentional control during visual target detection in emerging young adults as a function of binge drinking.

METHOD

In total, 51 first-year university students (18 ± 0.6 years) were assigned to light drinking ( n = 26), and binge drinking ( n = 25) groups based on their alcohol consumption patterns. A high-density magnetoencephalography signal was combined with structural magnetic resonance imaging in an anatomically constrained magnetoencephalography model to estimate event-related source power in a theta (4-7 Hz) frequency band. Phase-locked co-oscillations were further estimated between the principally activated regions during task performance.

RESULTS

Overall, the greatest event-related theta power was elicited by targets in the right inferior frontal cortex and it correlated with performance accuracy and selective attention scores. Binge drinkers exhibited lower theta power and dysregulated oscillatory synchrony to targets in the right inferior frontal cortex, which correlated with higher levels of alcohol consumption.

CONCLUSIONS

These results confirm that a highly interactive network in the right inferior frontal cortex subserves attentional control, revealing the importance of theta oscillations and neural synchrony for attentional capture and contextual maintenance. Attenuation of theta power and synchronous interactions in binge drinkers may indicate early stages of suboptimal integrative processing in young, highly functioning binge drinkers.

Can the gap in Aboriginal outcomes be explained by DOHaD

In Australia, there are two distinct populations, each with vastly disparate health outcomes: Aboriginal and Torres Strait Islander People and non-Aboriginal Australians. Aboriginal Australians have significantly higher rates of health and socioeconomic disadvantage, and Aboriginal babies are also more likely to be born low birth weight or growth restricted. The Developmental Origins of Health and Disease (DOHaD) hypothesis advocates that a sub-optimal intrauterine environment, often manifested as diminished foetal growth, during critical periods of foetal development has the potential to alter the risk of non-communicable disease in the offspring. A better understanding of the role of the intrauterine environment and subsequent developmental programming, in response to both transgenerational and immediate stimuli, in Aboriginal Australians remains a relatively unexplored field and may provide insights into the prevailing health disparities between Aboriginal and non-Aboriginal children. This narrative review explores the role of DOHaD in explaining the ongoing disadvantage experienced by Aboriginal People in today's society through a detailed discussion of the literature on the association between foetal growth, as a proxy for the quality of the intrauterine environment, and outcomes in the offspring including perinatal health, early life development and childhood education. The literature largely supports this hypothesis and this review therefore has potential implications for policy makers not only in Australia but also in other countries that have minority and Indigenous populations who suffer disproportionate disadvantage such as the United States, Canada and New Zealand.