Brain Growth Research Articles

Playing all day

Richard Willis, visiting professor at the University of South Wales, reviews a book which discusses how play affects brain growth and how children develop, up to the age of five. This innovative book incorporates multimedia to offer readers something more

Smarter foragers do not forage smarter: a test of the diet hypothesis for brain expansion.

A leading hypothesis for the evolution of large brains in humans and other species is that a feedback loop exists whereby intelligent animals forage more efficiently, which results in increased energy intake that fuels the growth and maintenance of large brains. We test this hypothesis for the first time with high-resolution tracking data from four sympatric, frugivorous rainforest mammal species (42 individuals) and drone-based maps of their predominant feeding trees. We found no evidence that larger-brained primates had more efficient foraging paths than smaller brained procyonids. This refutes a key assumption of the fruit-diet hypothesis for brain evolution, suggesting that other factors such as temporal cognition, extractive foraging or sociality have been more important for brain evolution.

Genetic variants for head size share genes and pathways with cancer

The size of the human head is highly heritable, but genetic drivers of its variation within the general population remain unmapped. We perform a genome-wide association study on head size (N= 80,890) and identify 67 genetic loci, of which 50 are novel. Neuroimaging studies show that 17 variants affect specific brain areas, but most have widespread effects. Gene set enrichment is observed for various cancers and the p53, Wnt, and ErbB signaling pathways. Genes harboring lead variants are enriched for macrocephaly syndrome genes (37-fold) and high-fidelity cancer genes (9-fold), which is not seen for human height variants. Head size variants are also near genes preferentially expressed in intermediate progenitor cells, neural cells linked to evolutionary brain expansion. Our results indicate that genes regulating early brain and cranial growth incline to neoplasia later in life, irrespective of height. This warrants investigation of clinical implications of the link between head size and cancer.

Role of the prefrontal cortical protease TACE/ADAM17 in neurobehavioral responses to chronic stress during adolescence.

Chronic adolescent stress profoundly affects prefrontal cortical networks regulating top-down behavior control. However, the neurobiological pathways contributing to stress-induced alterations in the brain and behavior remain largely unknown. Chronic stress influences brain growth factors and immune responses, which may, in turn, disrupt the maturation and function of prefrontal cortical networks. The tumor necrosis factor alpha-converting enzyme/a disintegrin and metalloproteinase 17 (TACE/ADAM17) is a sheddase with essential functions in brain maturation, behavior, and inflammatory responses. This study aimed to determine the impact of stress on the prefrontal cortex and whether TACE/ADAM17 plays a role in these responses. We used a Lewis rat model that incorporates critical elements of chronic psychosocial stress, such as uncontrollability, unpredictability, lack of social support, and re-experiencing of trauma. Chronic stress during adolescence reduced the acoustic startle reflex and social interactions while increasing extracellular free water content and TACE/ADAM17 mRNA levels in the medial prefrontal cortex. Chronic stress altered various ethological behavioral domains in the observation home cages (decreased ingestive behaviors and increased walking, grooming, and rearing behaviors). A group of rats was injected intracerebrally either with a novel Accell™ SMARTpool TACE/ADAM17 siRNA or a corresponding siRNA vehicle (control). The RNAscope Multiplex Fluorescent v2 Assay was used to visualize mRNA expression. Automated puncta quantification and analyses demonstrated that TACE/ADAM17 siRNA administration reduced TACE/ADAM17 mRNA levels in the medial prefrontal cortex (59% reduction relative to control). We found that the rats that received prefrontal cortical TACE/ADAM17 siRNA administration exhibited altered eating patterns (e.g., increased food intake and time in the feeding zone during the light cycle). This study supports that the prefrontal cortex is sensitive to adolescent chronic stress and suggests that TACE/ADAM17 may be involved in the brain responses to stress.

Executive functions and brain morphology of male and female dominant and subordinate cichlid fish.

Living in a social dominance hierarchy presents different benefits and challenges for dominant and subordinate males and females, which might in turn affect their cognitive needs. Despite the extensive research on social dominance in group-living species, there is still a knowledge gap regarding how social status impacts brain morphology and cognitive abilities. Here, we tested male and female dominants and subordinates of Neolamprologus pulcher, a social cichlid fish species with size-based hierarchy. We ran three executive cognitive function tests for cognitive flexibility (reversal learning test), self-control (detour test), and working memory (object permanence test), followed by brain and brain region size measurements. Performance was not influenced by social status or sex. However, dominants exhibited a brain-body slope that was relatively steeper than that of subordinates. Furthermore, individual performance in reversal learning and detour tests correlated with brain morphology, with some trade-offs among major brain regions like telencephalon, cerebellum, and optic tectum. As individuals' brain growth strategies varied depending on social status without affecting executive functions, the different associated challenges might yield a potential effect on social cognition instead. Overall, the findings highlight the importance of studying the individual and not just species to understand better how the individual's ecology might shape its brain and cognition.

Single Amino Acid Substitution in the Matrix Protein of Rabies Virus Is Associated with Neurovirulence in Mice.

Rabies is a fatal encephalitic infectious disease caused by the rabies virus (RABV). RABV is highly neurotropic and replicates in neuronal cell lines in vitro. The RABV fixed strain, HEP-Flury, was produced via passaging in primary chicken embryonic fibroblast cells. HEP-Flury showed rapid adaptation when propagated in mouse neuroblastoma (MNA) cells. In this study, we compared the growth of our previously constructed recombinant HEP (rHEP) strain-based on the sequence of the HEP (HEP-Flury) strain-with that of the original HEP strain. The original HEP strain exhibited higher titer than rHEP and a single substitution at position 80 in the matrix (M) protein M(D80N) after incubation in MNA cells, which was absent in rHEP. In vivo, intracerebral inoculation of the rHEP-M(D80N) strain with this substitution resulted in enhanced viral growth in the mouse brain and a significant loss of body weight in the adult mice. The number of viral antigen-positive cells in the brains of adult mice inoculated with the rHEP-M(D80N) strain was significantly higher than that with the rHEP strain at 5 days post-inoculation. Our findings demonstrate that a single amino acid substitution in the M protein M(D80N) is associated with neurovirulence in mice owing to adaptation to mouse neuronal cells.

Effects of maternal supplementation with DHA and/or egg yolk powder on monoamine homeostasis in the perinatal piglet brain

ABSTRACT Objectives Reports indicate that children of mothers who received docosahexaenoic acid (DHA) or egg yolk supplements during pregnancy have improved performance on cognitive tasks and brain growth; their combination has recently been demonstrated to modulate functional neuronal network connectivity in the human-relevant piglet brain. To expand upon this functional connectivity analysis, neurochemical evaluation to determine how dietary supplementation with one or both of these nutrients during the last trimester of pregnancy alters monoamine homeostasis in selected brain regions of piglets was done. Methods Beginning gestation days 60–69 through weaning, pregnant sows were fed either control diet or diets supplemented with egg yolk powder, DHA, or both. Brains were then collected, and monoamine neurotransmitters and their metabolites were quantified from various brain regions with HPLC-ECD. Results Relative to controls, egg yolk supplementation increased serotonin metabolite (5-HIAA) levels in the cerebellum, while DHA supplementation decreased serotonin (5-HT) levels in the prefrontal cortex; combined supplementation increased norepinephrine metabolite (MHPG) levels in the prefrontal cortex and cerebellum, but decreased 5-HT levels in the posterior hippocampus. Notably, all diets increased serotonin, dopamine, and their respective metabolite levels in the substantia nigra. Disscussion This suggests both overlapping and specific effects of DHA and components of egg yolk in the context of maternal supplementation during pregnancy and lactation that might facilitate optimal neurodevelopment, with the nigrostriatal pathway being particularly sensitive. Such supplementations might impact brain function and facilitate development later in life through modulating monoamine homeostasis.

A new type of blood-brain barrier aminoacidopathy underlies metabolic microcephaly associated with SLC1A4 mutations.

Mutations in the SLC1A4 transporter lead to neurodevelopmental impairments, spastic tetraplegia, thin corpus callosum, and microcephaly in children. SLC1A4 catalyzes obligatory amino acid exchange between neutral amino acids, but the physiopathology of SLC1A4 disease mutations and progressive microcephaly remain unclear. Here, we examined the phenotype and metabolic profile of three Slc1a4 mouse models, including a constitutive Slc1a4-KO mouse, a knock-in mouse with the major human Slc1a4 mutation (Slc1a4-K256E), and a selective knockout of Slc1a4 in brain endothelial cells (Slc1a4tie2-cre). We show that Slc1a4 is a bona fide L-serine transporter at the BBB and that acute inhibition or deletion of Slc1a4 leads to a decrease in serine influx into the brain. This results in microcephaly associated with decreased L-serine content in the brain, accumulation of atypical and cytotoxic 1-deoxysphingolipids in the brain, neurodegeneration, synaptic and mitochondrial abnormalities, and behavioral impairments. Prenatal and early postnatal oral administration of L-serine at levels that replenish the serine pool in the brain rescued the observed biochemical and behavioral changes. Administration of L-serine till the second postnatal week also normalized brain weight in Slc1a4-E256 K mice. Our observations suggest that the transport of "non-essential" amino acids from the blood through the BBB is at least as important as that of essential amino acids for brain metabolism and development. We proposed that SLC1A4 mutations cause a BBB aminoacidopathy with deficits in serine import across the BBB required for optimal brain growth and leads to a metabolic microcephaly, which may be amenable to treatment with L-serine.

A study to assess the effectiveness of planned teaching regarding the harmful effect of oil application on anterior fontanels of newborn among post-natal mothers

The anterior fontanelle, sometimes known as the “soft spot,” is an important anatomical component in neonates that allows brain growth and development. Possible harm is caused by such practices, as they may result in unfavorable outcomes, such as skin irritation and a delay in fontanelle closure. The goal of this study was to see how effective pre-planned education was at informing postpartum women about the dangers of applying oil to newborns’ anterior fontanelles. The study was conducted with the goal of increasing the understanding of the adverse effects of oil application on the anterior fontanels of newborns among postnatal mothers, The study will be thoroughly described to the participants, and their written Consent will be taken for the participate in the study and publishing the information. Sampling technique will be convenient. Population and sampling techniques will be examined. Mothers will be the target group with a sample size of 60 postnatal mothers. The sample will be drawn using The Purposive sampling approach. Prior authorization will be acquired from the designated hospitals’ higher authority. The inclusion criteria will be used to select samples. Information will be gathered from the hospital’s obstetric ward. First, pretest knowledge of the adverse effects of applying oil to newborns’ anterior fontanels among postnatal mothers was assessed. Postnatal mothers will be taught about the detrimental effects of placing oil on the anterior fontanels of their newborns. The post-test assessment of knowledge regarding the adverse effects of applying oil to anterior fontanels was performed after 7 days. If the hypothesis of our study is helpful in improving mothers’ knowledge in the post-test rather than pre-test following the intended training.

Severe Bronchopulmonary Dysplasia Adversely Affects Brain Growth in Preterm Infants

Introduction: Bronchopulmonary dysplasia (BPD) is associated with neurodevelopmental outcomes of preterm infants, but its effect on brain growth in preterm infants after the neonatal period is unknown. This study aimed to evaluate the effect of severe BPD on brain growth of preterm infants from term to 18 months of corrected age (CA). Methods: Sixty-three preterm infants (42 with severe BPD and 21 without severe BPD) who underwent magnetic resonance imaging at term equivalent age (TEA) and 18 months of CA were studied by using the Infant Brain Extraction and Analysis Toolbox (iBEAT). We measured segmented brain volumes and compared brain volume and brain growth velocity between the severe BPD group and the non-severe BPD group. Results: There was no significant difference in brain volumes at TEA between the groups. However, the brain volumes of the total brain and cerebral white matter in the severe BPD group were significantly smaller than those in the non-severe BPD group at 18 months of CA. The brain growth velocities from TEA to 18 months of CA in the total brain, cerebral cortex, and cerebral white matter in the severe BPD group were lower than those in the non-severe BPD group. Conclusion: Brain growth in preterm infants with severe BPD from TEA age to 18 months of CA is less than that in preterm infants without severe BPD.

Safety and feasibility pilot study of continuous low-dose maternal supplemental oxygen in fetal single ventricle heart disease.

Fetuses with single ventricle physiology (SVP) exhibit reductions in fetal cerebral oxygenation, with associated delays in fetal brain growth and neurodevelopmental outcomes. Maternal supplemental oxygen (MSO) has been proposed to improve fetal brain growth, but current evidence on dosing, candidacy and outcomes is limited. In this pilot study, we evaluated the safety and feasibility of continuous low-dose MSO in the setting of SVP. This single-center, open-label, pilot phase-1 safety and feasibility clinical trial included 25 pregnant individuals with a diagnosis of fetal SVP. Participants self-administered continuous MSO using medical-grade oxygen concentrators for up to 24 h per day from the second half of gestation until delivery. The primary aim was the evaluation of the safety profile and feasibility of MSO. A secondary preliminary analysis was performed to assess the impact of MSO on the fetal circulation using echocardiography and late-gestation cardiovascular magnetic resonance imaging. Early outcomes were assessed, including perinatal growth and preoperative brain injury, and neurodevelopmental outcomes were assessed at 18 months using the Bayley Scales of Infant and Toddler Development 3rd edition, and compared with those of a contemporary fetal SVP cohort (n = 217) that received the normal standard of care (SOC). Among the 25 participants, the median maternal age at conception was 35 years, and fetal SVP diagnoses included 16 with right ventricle dominant, eight with left ventricle dominant and one with indeterminate ventricular morphology. Participants started the trial at approximately 29 + 2 weeks' gestation and self-administered MSO for a median of 16.1 h per day for 63 days, accumulating a median of 1029 h of oxygen intake from enrolment until delivery. The only treatment-associated adverse events were nasal complications that were resolved typically by attaching a humidifier unit to the oxygen concentrator. No premature closure of the ductus arteriosus or unexpected fetal demise was observed. In the secondary analysis, MSO was not associated with any changes in fetal growth, middle cerebral artery pulsatility index, cerebroplacental ratio or head-circumference-to-abdominal-circumference ratio Z-scores over gestation compared with SOC. Although MSO was associated with changes in umbilical artery pulsatility index Z-score over the study period compared with SOC (P = 0.02), this was probably due to initial baseline differences in placental resistance. At late-gestation cardiovascular magnetic resonance imaging, MSO was not associated with an increase in fetal cerebral oxygen delivery. Similarly, no differences were observed in neonatal outcomes, including preoperative brain weight Z-score and brain injury, mortality by 18 months of age and neurodevelopmental outcomes at 18 months of age. This pilot phase-1 clinical trial indicates that low-dose MSO therapy is safe and well tolerated in pregnancies diagnosed with fetal SVP. However, our protocol was not associated with an increase in fetal cerebral oxygen delivery or improvements in early neurological or neurodevelopmental outcomes. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Selection and Increasing Complexity in Evolution

This paper explores the concept of complexity in the evolution of life and human culture, proposing that the overarching increase in complexity is driven by the fundamental mechanism of selection. From the origin of life to contemporary human culture, selection plays a pivotal role in favoring complexity in reproductive processes and cultural expressions. The paper distinguishes two main phases of life on Earth: the emergence and evolution of life and animals, and the subsequent emergence of the human species with its complex cultural expressions. Despite apparent differences, both phases are argued to be guided by the same fundamental mechanism—selection, taking various forms such as adaptive natural selection, non-adaptive selection, sexual selection, and memetic selection. The paper identifies the acquisition of language as a crucial development, influenced by imitation and sexual selection, and suggests that the strong selective pressure for language has driven the rapid growth of the human brain and intelligence. This enhanced intelligence, in turn, has played a pivotal role in cultural, scientific, and technological achievements marked by unprecedented levels of complexity. The role of memetic selection is explored in the dissemination of religion across human societies, and the unintended consequences of Martin Luther's introduction of literacy and schooling for Western culture are examined. By integrating evolutionary principles with cultural and linguistic insights, this paper offers a comprehensive perspective on the unifying force of selection in the evolution of complexity in life and human culture.

KMC and Brain Development: A Plea for Starting KMC as Early as Possible and as Long as Possible

The kangaroo mother care (KMC) method is a “45-year-old innovation” in health care to care for premature or low birth weight (LBW) infants: the KMC position with direct skin-to-skin contact on the chest of the mother, KMC nutrition based on breast milk and early home discharge in KMC position with close monitoring are the three key elements of this intervention. Created in 1978 to compensate for the lack of incubators in a huge maternity hospital in Colombia, it has always met with resistance from health professionals. Rigorously studied, it has shown benefits far beyond the reduction in mortality, to ensure a proper quality of life for these fragile babies. KMC has become an example of evidence-based care for premature or LBW infants, and it is no longer ethical not to apply it. Exploratory analysis results on brain growth according to the duration in days of KMC position are presented in this article and should help accelerate the systematic introduction of KMC as early as possible and for as long as possible from birth, as published by the WHO in 2022.

Astaxanthin and DHA Supplementation Modulates the Maternal Undernutrition-induced Impairment of Cognitive Behavior and Synaptic Plasticity in Adult Life of Offspring's -Exploring the Molecular Mechanism.

Maternal nutrition was recognized as a significant part of brain growth and maturation in most mammalian species. Timely intervention with suitable nutraceuticals would provide long-term health benefits. We aim to unravel the molecular mechanisms of perinatal undernutrition-induced impairments in cognition and synaptic plasticity, employing animal model based on dietary nutraceutical supplementation. We treated undernourished dams at their gestational, lactational, and at both the time point with Astaxanthin (AsX) and Docosahexaenoic acid (DHA), and their pups were used as experimental animals. We evaluated the cognitive function by subjecting the pups to behavioral tests in their adult life. In addition, we assessed the expression of genes in the hippocampus related to cognitive function and synaptic plasticity. Our results showed downregulation of Brain-derived neurotrophic factor (BDNF), Neurotrophin-3 (NT-3), cAMP response-element-binding protein (CREB), and uncoupling protein-2 (UCP2) gene expression in pups born to undernourished dams in their adult life, which AsX and DHA modulated. Maternal AsX and DHA supplementation ameliorated the undernutrition-induced learning impairment in novel object recognition (NOR) tests and partially baited radial arm maze (RAM) tasks in offspring's. The expressions of Synapsin-1 and PSD-95 decreased in perinatally undernourished groups compared to control and AsX-DHA treated groups at CA1, CA2, CA3, and DG. AsX and DHA supplementation upregulated BDNF, NT-3, CREB, and UCP2 gene expressions in perinatally undernourished rats, which are involved in intracellular signaling cascades like Ras, PI3K, and PLC. The results of our study give new insights into neuronal differentiation, survival, and plasticity, indicating that the perinatal period is the critical time for reversing maternal undernutrition-induced cognitive impairment in offspring's.

Longitudinal MRI of the developing ferret brain reveals regional variations in timing and rate of growth.

Normative ferret brain development was characterized using magnetic resonance imaging. Brain growth was longitudinally monitored in 10 ferrets (equal numbers of males and females) from postnatal day 8 (P8) through P38 in 6-d increments. Template T2-weighted images were constructed at each age, and these were manually segmented into 12 to 14 brain regions. A logistic growth model was used to fit data from whole brain volumes and 8 of the individual regions in both males and females. More protracted growth was found in males, which results in larger brains; however, sex differences were not apparent when results were corrected for body weight. Additionally, surface models of the developing cortical plate were registered to one another using the anatomically-constrained Multimodal Surface Matching algorithm. This, in turn, enabled local logistic growth parameters to be mapped across the cortical surface. A close similarity was observed between surface area expansion timing and previous reports of the transverse neurogenic gradient in ferrets. Regional variation in the extent of surface area expansion and the maximum expansion rate was also revealed. This characterization of normative brain growth over the period of cerebral cortex folding may serve as a reference for ferret studies of brain development.

The Peran Intervensi Gizi Sensitif (Program Kesehatan Lingkungan, Masalah Kemiskinan dan Pemberdayaan Perempuan) dalam Perbaikan Masalah Gizi Balita Stunting di Kelurahan Landasan Ulin Utara

Stunting is defined as a state of short or very short stature caused by linear growth that fails to reach its proper genetic potential. Stunting affects brain growth and development. Stunted children also have a higher risk of suffering from chronic diseases in their adult years. Stunting reduction requires integrated interventions, including specific nutrition interventions and sensitive nutrition interventions. This study aims to identify sensitive nutritional interventions (environmental health programs, poverty issues and women's empowerment) in overcoming the nutritional problem of stunting toddlers. This type of research is qualitative which is analyzed descriptively and in-depth interviews and observations with research samples are informants from the non-health sector, namely village heads, RW heads, RT heads, PKK. The sampling technique was carried out by purposive sampling technique. This research was conducted in the Village of Landasan Ulin Utara, Banjarbaru City. The results showed sensitive nutritional interventions for environmental health (clean Saturday or Sunday program, mutual cooperation, and eco engine training), poverty issues (keluarga harapan program, provision of BST, BLT BBM, KIS, BPJS, PNPM, and business equipment assistance), and women's empowerment (DASHAT program, MSME training, seed and livestock assistance). Sensitive nutritional interventions can be carried out on an ongoing basis and combined with specific nutritional interventions in handling stunting toddler nutritional problems.

Analysis of Head Circumference, Exclusive Breastfeeding, and Child Development at Kedaung Community Health Center

Background: Head circumference is one of the indicators for assessing intracranial volume and brain growth. Development is the improvement of bodily functions and abilities, such as emotional, intellectual, and behavioral development. Breast milk is a source of intake for nutrients for newborns who can support maximum growth and development. Purposes: It is known that the relationship between head circumference and development with the Developmental Pre-Screening Questionnaire (DPsQ) in children aged 3 – 6 months who get breast milk or formula milk in work area of the Kedaung Community Health Center Depok City. Methods: The design is a cross-sectional analytic study with respondents mothers who had a child and got breast milk at least three months after birth. The sampling technique used a convenience sampling method to obtain as many as 50 mothers, and the analysis data was analyzed using statistical methods using the chi-square test. Results: Children with the majority of 3 and 4 months of age were 34% each, female at 52%, breastfeeding alone at 80%, normal head circumference at 98%, and age-appropriate development in general by 90%. There was a significant relationship between head circumference size and breast milk status with DPsQ value and interpretation (p-value=0.002 OR=12.250 CI95%=4.789-31.333); (p-value=0.018 OR=8.143 CI95%=1.144-57.949). Conclusion: There is a 12 times greater relationship between head circumference size and development and an eight times more significant relationship between breast milk status and development in infants aged 3 – 6 months who get breast milk in the work area of the Kedaung Community Health Center Depok City.

Computer Aided Diagnosis of Brain Tumour Using Walrus Optimization Algorithm

Brain tumour segmentation is one of the most challenging problems in medical image analysis. To detect brain cancers, radiologists must use a computer-based tumour classification model. In medical imaging research, several computer-aided diagnostic (CAD) models are available to help radiologists with their patients. The reason for brain growth division is to deliver exact outline of brain tumour regions. This study suggests a Walrus Optimisation Algorithm approach for detecting brain tumours using MRI (Magnetic Resonance Imaging). Separating the characteristics into four categories has been utilized: no growth, gliomas, meningiomas, and pituitary cancers. The deep learning based model inception AlexNet and ResNet-18 is trained on an augmented training dataset. The CNN classifier is used for characteristics map improvement, while the LSTM (Long momentary memory) classifier is utilized for order. Besides, the boundary remembered for the classifiers is chosen aimlessly utilizing the Walrus Improvement Calculation to build the presentation of the CNN-LSTM classifier. The performance of the tumour diagnosis is assessed using the metrics: overall classification accuracy of 98.8%, precision of 96.23%, recall of 97.01%, specificity of 98%.

Imaging Genomics of Glioma Revisited: Analytic Methods to Understand Spatial and Temporal Heterogeneity.

An improved understanding of the cellular and molecular biologic processes responsible for brain tumor development, growth, and resistance to therapy is fundamental to improving clinical outcomes. Imaging genomics is the study of the relationships between microscopic, genetic, and molecular biologic features and macroscopic imaging features. Imaging genomics is beginning to shift clinical paradigms for diagnosing and treating brain tumors. This article provides an overview of imaging genomics in gliomas, in which imaging data including hallmarks such as IDH-mutation, MGMT methylation, and EGFR-mutation status can provide critical insights into the pretreatment and posttreatment stages. This article will accomplish the following: 1) review the methods used in imaging genomics, including visual analysis, quantitative analysis, and radiomics analysis; 2) recommend suitable analytic methods for imaging genomics according to biologic characteristics; 3) discuss the clinical applicability of imaging genomics; and 4) introduce subregional tumor habitat analysis with the goal of guiding future radiogenetics research endeavors toward translation into critically needed clinical applications.

Examining the interaction between prenatal stress and polygenic risk for attention-deficit/hyperactivity disorder on brain growth in childhood: Findings from the DREAM BIG consortium.

This study explored the interactions among prenatal stress, child sex, and polygenic risk scores (PGS) for attention-deficit/hyperactivity disorder (ADHD) on structural developmental changes of brain regions implicated in ADHD. We used data from two population-based birth cohorts: Growing Up in Singapore Towards healthy Outcomes (GUSTO) from Singapore (n=113) and Generation R from Rotterdam, the Netherlands (n=433). Prenatal stress was assessed using questionnaires. We obtained latent constructs of prenatal adversity and prenatal mood problems using confirmatory factor analyses. The participants were genotyped using genome-wide single nucleotide polymorphism arrays, and ADHD PGSs were computed. Magnetic resonance imaging scans were acquired at 4.5 and 6 years (GUSTO), and at 10 and 14 years (Generation R). We estimated the age-related rate of change for brain outcomes related to ADHD and performed (1) prenatal stress by sex interaction models, (2) prenatal stress by ADHD PGS interaction models, and (3) 3-way interaction models, including prenatal stress, sex, and ADHD PGS. We observed an interaction between prenatal stress and ADHD PGS on mean cortical thickness annual rate of change in Generation R (i.e., in individuals with higher ADHD PGS, higher prenatal stress was associated with a lower rate of cortical thinning, whereas in individuals with lower ADHD PGS, higher prenatal stress was associated with a higher rate of cortical thinning). None of the other tested interactions were statistically significant. Higher prenatal stress may promote a slower brain developmental rate during adolescence in individuals with higher ADHD genetic vulnerability, whereas it may promote a faster brain developmental rate in individuals with lower ADHD genetic vulnerability.