Latest news with #DevelopingHumanConnectomeProject
Express Tribune
21-03-2025
- Health
- Express Tribune
Study finds sex-based brain differences present at birth and stable in early infancy
A new study published in Biology of Sex Differences has revealed that structural differences between male and female brains are present from birth and remain relatively unchanged during the first month of life, highlighting the significant role of prenatal biological factors in shaping early brain development. The research, conducted by scientists from the University of Cambridge as part of the Developing Human Connectome Project, analyzed brain scans of 514 full-term, healthy newborns — 278 boys and 236 girls — all within the first 28 days of life. Using magnetic resonance imaging (MRI), researchers found that male infants had larger overall brain volumes, a pattern that aligns with findings in older children and adults. However, after adjusting for total brain size, female infants were found to have more grey matter, the part of the brain responsible for information processing, while male infants had more white matter, which facilitates communication between brain regions. Lead author Yumnah Khan, a PhD student at the University of Cambridge, said the findings challenge long-held assumptions that such sex-based differences in the brain are largely the result of social or environmental influences. 'Several on-average sex differences in the brain are already present from birth, indicating that prenatal factors play an important role in initiating sex differences in the brain,' Khan told PsyPost. Exploring structural brain differences The MRI scans revealed specific brain regions where the sexes differed. Female infants had relatively greater volumes in the corpus callosum, the bridge between the brain's hemispheres, and the parahippocampal gyrus, linked to memory. Meanwhile, male infants showed larger volumes in the medial and inferior temporal gyri, areas associated with visual and auditory processing. Notably, these differences remained stable throughout the first month of life, suggesting they were established before birth rather than shaped by early postnatal experiences. 'We found it very interesting that several of the sex differences that were previously observed in older children and adults were already present at birth,' Khan said. 'This emphasises that these differences are present from the very beginning of life and likely emerge prenatally.' Implications for neurodevelopmental research The findings have important implications for understanding why certain neurological and psychiatric conditions — such as autism, ADHD, and depression — occur more frequently or present differently in males and females. Researchers say these conditions may be linked to early structural differences in the brain, offering a potential pathway for earlier identification and targeted interventions. Khan emphasised that the interest in sex differences is not just academic, but also practically significant. 'A better understanding of sex differences, their underlying causes, and the timeline of their emergence can explain why certain disorders affect males and females differently. This may also help tailor diagnostic and support strategies to improve health outcomes,' she said. Caution against overgeneralisation Despite the findings, the researchers were careful to warn against overinterpreting the results. The differences observed are average differences across large groups and do not suggest that male and female brains are fundamentally or universally different in function. 'It is important not to overstate or exaggerate the differences,' Khan explained. 'The brain is not 'sexually dimorphic' like reproductive organs. The brains of males and females are more similar than they are different.' The study did not investigate whether the observed structural differences translate into behavioral or cognitive differences, nor did it explore the precise causes — whether genetic, hormonal, or environmental — of these early brain differences. 'There is still much more to uncover,' Khan said. 'We now need to determine whether these structural differences are linked to behavior, cognition, or future developmental outcomes. Understanding the origins and implications of these differences is the next critical step.' This research marks one of the most detailed investigations into sex differences in the neonatal brain, offering a foundational understanding of how male and female brains begin to diverge—if only slightly—from the very first days of life. It also adds to the growing body of evidence that biological sex plays a role in brain development from the earliest stages, long before social and cultural influences take hold.
Iraqi News
06-02-2025
- Health
- Iraqi News
Autism risk genes linked to white matter changes at birth, shaping early brain development
In a recent study published in the journal Translational Psychiatry, a group of researchers investigated the relationship between common genetic variants associated with autism and structural variations in white matter among term-born neonates, highlighting potential associations that may contribute to future research on early autism markers rather than serving as definitive biomarkers. Background Autism Spectrum Disorder (ASD) affects approximately 1 in 100 children worldwide, yet early diagnosis remains a challenge. Emerging research suggests that differences in white matter—the brain's communication network—can be detected in infancy and may serve as early indicators of autism. White matter develops rapidly during pregnancy and infancy, forming essential neural connections that support cognition and motor function. Genetic factors play a crucial role in this process, but their exact influence remains unclear. Advances in neuroimaging now allow researchers to map these early brain changes, shedding light on how genetic predisposition shapes neural pathways. Understanding these links may lead to earlier interventions, improving outcomes for children at risk of autism. While studies have explored white matter differences in older children, little is known about how genetic variants influence neonatal brain structure, necessitating further investigation. About the Study The present study analyzed white matter structures in 221 term-born infants of European ancestry from the Developing Human Connectome Project. Advanced diffusion-weighted imaging was used to capture high-resolution brain scans, allowing researchers to examine microscopic fiber density and macrostructural morphology. Data preprocessing included noise reduction, motion correction, and normalization to a study-specific brain template. Genetic analysis involved saliva samples collected at birth or 18 months, which were processed to identify common genetic markers associated with autism. Quality control measures ensured data reliability, excluding samples with incomplete genetic information. Polygenic scores, representing cumulative autism risk, were calculated based on genome-wide association studies and adjusted for ancestry differences. Statistical models assessed the relationship between genetic risk and white matter structure, accounting for variables such as total brain volume, gestational age, and sex. A gene-set enrichment analysis was conducted to identify biological pathways linked to white matter alterations associated with autism. Additional analyses were performed to explore whether specific genetic pathways influenced structural differences in white matter connectivity. Study Results Infants with higher autism polygenic scores showed a significant increase in fiber-bundle cross-section in the left superior corona radiata, a brain region crucial for motor and cognitive functions. This suggests that genetic predisposition to autism may shape early white matter organization, though further studies are needed to confirm its significance for later developmental outcomes. Further analysis indicated that microscopic white matter properties remained unchanged, while macrostructural differences were prominent in the superior corona radiata and related tracts. These findings align with previous studies reporting increased white matter volume in infants and toddlers later diagnosed with autism. However, the study did not find significant microstructural differences, suggesting that the observed changes are more related to fiber bundle cross-section rather than density or organization at the microscopic level. A deeper investigation into brain connectivity patterns revealed that infants with higher autism polygenic scores had increased cross-sectional areas in additional white matter tracts, including pathways involved in sensorimotor and cognitive processing. These changes could play a role in the atypical brain connectivity observed in individuals with autism. Genetic pathway analysis revealed that the autism-associated variants linked to white matter changes were overrepresented in genes related to neuronal connectivity and synaptic function. Notably, genes such as MAPT, KCNN2, and DSCAM—previously implicated in autism risk—were highlighted in the study, reinforcing the hypothesis that white matter alterations are linked to neurodevelopmental processes essential for cognitive and motor function. While statistically significant, the effect sizes were small, and some findings—such as those related to the right superior corona radiata—did not survive multiple testing corrections, indicating the need for further validation. These findings suggest that white matter alterations in neonates reflect genetic influences on early brain development rather than serving as definitive biomarkers for autism. If validated in larger studies, these results could have profound implications for early screening and intervention strategies, enabling proactive developmental support before behavioral symptoms emerge. Conclusions To summarize, these findings emphasize the profound impact of genetics on early brain development. By identifying structural brain differences at birth, researchers move closer to understanding autism's earliest origins. Detecting these alterations early could contribute to research on personalized interventions, allowing for targeted therapies before behavioral symptoms emerge. However, the study does not suggest that current neuroimaging techniques can reliably predict autism in neonates. As neuroscience advances, integrating genetic insights with neuroimaging may help predict neurodevelopmental outcomes, ultimately improving the lives of individuals with autism and their families. Future research should explore how these early structural changes relate to long-term cognitive and behavioral development, shaping new strategies for early intervention and support.
