Biology subjects

Arichi, T.

Publications and source records attributed to Arichi, T..

At least 19 recordsLinked to original sources

bioRxiv2026

Early development of cerebellar functional connectivity

The cerebellum makes a critical contribution to cognitive and behavioural function, extending well beyond motor control, and is recognised as an important determinant of neurodevelopmental outcome. Despite this, little is known about the foundations of cerebellar functional organisation in early life. Addressing this gap is essential for establishing typical developmental trajectories against which atypical development can be assessed. Here, we analysed fMRI data from term-born neonates (n=155) scanned between 37 and 44 weeks postmenstrual age and mapped intra-cerebellar and cerebro-cerebellar functional connectivity across multiple levels of organisation. We identified 13 intrinsic connectivity networks (ICNs) within the neonatal cerebellum that recapitulated adult subdivisions, with two ICNs showing age-related increases in coverage and strength. Analysis of cerebro-cerebellar connectivity identified 15 sensory, motor and association cerebral clusters, seven increasing connectivity with age. Functional gradient analysis identified a continuous axis from somatomotor to association regions within intra-cerebellar and cerebro-cerebellar organisation, which became more pronounced with age. Together, these findings suggest that the foundations of adult cerebellar functional organisation are present at birth but undergo rapid and regionally heterogeneous maturation over the first weeks of postnatal life. This developmental framework provides a normative reference for understanding cerebellar development and its implications for later neurodevelopmental variation.

neuroscience↗

bioRxiv2026

Development of Neonatal Functional Brain Network Organisation and Its Association with Childhood Neurodevelopmental Outcomes

The human brain undergoes rapid dynamic changes in the neonatal period that are essential for later cognitive and behavioural performance. Using resting-state fMRI data from 394 neonates (325 term-born, 69 preterm-born) within the first month after birth, we characterised the early development of functional network organisation, the effects of preterm birth, and the association between neonatal functional organisation and later neurodevelopmental outcomes in infancy (18 months) and childhood (4-6 years). We found increased functional integration and segregation across a wide range of functional sub-networks and increased mean functional connectivity strength (mean FCS) within the subcortical and cerebellar regions with increasing PMA at scan. Compared with term-born neonates, preterm-born neonates showed significantly lower mean FCS, functional integration and segregation globally. We further showed that whilst neonatal functional brain network organisation was not associated with neurodevelopmental outcomes measured during infancy (18 months), it was associated with later neurodevelopmental outcomes in early childhood (4-6 years). Specifically, higher functional integration and segregation at birth were linked with lower SDQ total difficulties score at 4-6 years. Our findings suggest that neonatal functional brain organisation reflects not only transient developmental processes, but also stable individual differences that provide insight into neurodevelopmental outcomes in later childhood.

neuroscience↗

bioRxiv2026

Emergence of long- and short-range functional connectivity shapes neonatal brain gradients

The emergence of macroscale brain organisation during the perinatal period represents a critical but poorly understood process. Using resting-state fMRI in 325 term-born neonates within the first month of postnatal life, we characterised the early emergence of macroscale brain organisation with functional gradients. Neonatal functional gradients showed a distinct pattern compared with the canonical adult gradients: the principal gradient in neonates, separating the primary sensorimotor and visual networks, corresponded to the secondary gradient in adults (sensorimotor-visual axis), whereas the secondary gradient in neonates, spanning from primary visual to association networks, aligned with the principal gradient in adults (sensorimotor-association axis). We identified distance-dependent functional connectivity as a key mechanism shaping perinatal functional gradients and potentially underlying the protracted development of the sensorimotor-association hierarchy in neonates. Regions with a higher proportion of short-range functional connectivity contributed more to the sensorimotor-visual gradient in neonates, while regions with a greater proportion of middle-to long-range functional connectivity drive the sensorimotor-association hierarchy. Together, these findings highlight the critical role of short- and long-range functional connectivity in shaping neonatal macroscale functional hierarchy. Disruptions to this process during the perinatal period may alter macroscale brain organisation and contribute to the early origins of neurodevelopmental conditions. Significance statementMacroscale brain organisation, characterised by functional gradients, is a fundamental feature of the adult brain and is closely linked to neurodevelopmental conditions. Characterising its emergence in early life and the underlying mechanisms is therefore critical for understanding typical and atypical brain development. Here, we showed that macroscale brain organisation is present at birth, with neonatal functional gradients showing a reversed pattern compared to adults, highlighting the early maturation of primary visual and sensorimotor networks. We further demonstrated that the perinatal development of long- and short-range functional connectivity shapes neonatal functional gradients, identifying a potential mechanism through which early disruptions in functional connectivity may contribute to later neurodevelopmental outcomes.

neuroscience↗

bioRxiv2026

Simultaneous EEG-fMRI investigation of sound sequence processing in human neonates

The ability to detect sensory regularities and their violations (i.e. deviance) is fundamental for learning and the orientation of attention across the lifespan. This starts from the prenatal period, where the environment is rich in regular patterns and deviations of auditory stimulation which likely provides the basis for the emergence of early learning capacities. Following birth, EEG recordings of brain activity have demonstrated that neonates detect violations of regularity and show a robust mismatch response to deviant auditory stimuli. However, it is unknown how this processing is integrated across wider regions within emergent brain networks. To gain comprehensive insight into both the temporal and spatial properties of the processing underlying sensory deviance detection in the neonatal brain, we acquired simultaneous EEG and fMRI data in sleeping neonates during an auditory oddball paradigm. A mismatch response was identified with EEG when a deviant sound appeared after a sequence of identical sounds but not when a sound was omitted, suggesting encoding of deviances that violated local sequence regularity, but not global sequence structure. Simultaneous fMRI demonstrated engagement of distributed cortical networks during sound sequence processing, encompassing temporal, sensori-motor, and inferior frontal cortices, as well as subcortical regions including the thalamus and hippocampus. Deviance detection was associated with activity in the superior and ventromedial (hippocampus and parahippocampus) parts of the temporal lobe, and the precentral gyrus. Together, these findings suggest that neonatal brain detects deviance in sound sequences through the encoding of local regularities, supported by distinct processing pathways within sensory and limbic systems. These insights help advance our understanding of early auditory learning mechanisms, with implications for understanding how atypical developmental trajectories may emerge in these substrates.

neuroscience↗

bioRxiv2025

7 Tesla fMRI characterisation of the cortical-depth-dependentBOLD response in early human development

Human cortical development leading up to and around birth is crucial for lifelong brain function. Cortical activity can be studied using BOLD fMRI, however, previously limited sensitivity and spatial specificity has constrained understanding of how its emergence relates to functional cortical circuitry and neurovascular development at the mesoscale. To resolve this, we used ultra-high-field 7 Tesla MRI to acquire sub-millimetre resolution BOLD-fMRI data from 40 newborns and 4 adults. In all subjects, passive right-hand movement elicited localised, positive BOLD responses in contralateral primary somatosensory cortex. In newborns, depth-specific BOLD responses were still evident in the thinner cortex, with developmental changes in response temporal features and amplitudes at different depths. This provides insight into key rapidly evolving factors in early cortical development including neuronal function, vascular architecture, and neurovascular coupling. Our framework and findings provide a foundation for future studies of emerging cortical circuitry and how disruption leads to adverse outcomes.

developmental biology↗

bioRxiv2025

Functional covariance modes reveal aligned fetal and neonatal brain functional connectomes.

Spatially distributed functional networks are a fundamental property of brain organisation. While these networks are already present at full-term birth, establishing whether they exist before birth remains problematic, given the challenges inherent to in utero fMRI. Here, we introduce a seed-based functional covariance modes (FCMs) approach, which leverages inter-subject variability in connectivity between distinct regions and the rest of the brain to infer whole-brain network configurations. Unlike standard group-level independent component analysis, which consistently fails to reveal spatially distributed neural networks in fetal populations, FCMs successfully delineated a range of brain-wide functional networks in utero with high spatial fidelity to neonatal network maps, including bilateral organisation - a landmark feature of many neonatal functional networks. Furthermore, we demonstrated that bilateral fetal networks preferentially clustered along the brain midline and around cortical limbic territories. In contrast, single-hemisphere dominant networks mapped into areas associated with hemispheric functional asymmetry in the mature brain, including the highly lateralised language circuits. Together, these findings provide coherent evidence that the blueprint for the functional brain architecture, including its functional specialisation, is formed before birth.

neuroscience↗

bioRxiv2025

Characterising the association between posterior parietal metabolite levels and cortical macrostructure in a cohort spanning childhood to adulthood.

Postnatal brain development is characterised by dynamic macrostructural changes, including cortical thinning and cortical flattening during childhood and adolescence. These macro-structural changes are parallel with developmental changes in brain neurochemistry, probed in the human brain using Magnetic Resonance Spectroscopy (MRS). This includes neurotransmitters such glutamate and gamma-aminobutyric acid (GABA), as well as building blocks of neuronal and associated tissue such as N-acetyl aspartate (NAA), and those involved in metabolism such as creatine (Cr). While previous research has linked MRS-measured neuro-metabolite levels to bulk tissue composition (e.g., gray matter, white matter, and cerebrospinal fluid), the relationship between neurochemistry and more granular macrostructural metrics, such as cortical thickness, area, volume, and local gyrification, remains unexplored. This study investigates the association between MRS-measured neuro-metabolite levels in the posterior parietal cortex (PPC) and PPC-voxel cortical macrostructural metrics in a developmental cohort of 86 individuals aged 5-35 years. We also examine whether PPC metabolite concentrations associate with whole-brain structural metrics to determine whether associations are region-specific or more broadly generalisable. Our findings reveal significant positive associations between PPC cortical thickness, volume, local gyrification index (LGI) and Glx (glutamate + glutamine) levels, likely because differences in cortical microstructure, including dendritic arbour complexity, contributes to variation in both cortical macrostructure and Glx activity across development. Additionally, PPC Glx:GABA+ ratio negatively associated with subcortical gray matter volume, while PPC total NAA positively associated with cerebral white matter volume, suggesting a link between regional neurochemistry and broader brain structure. These results highlight the importance of accounting for macrostructural and broader brain structural characteristics when interpreting the neuroanatomical correlates of MRS-measured metabolites, beyond controlling for bulk tissue composition. This approach is particularly crucial when comparing neuro-metabolite levels across groups with known structural differences, such as developmental cohorts or individuals with neurodevelopmental conditions. Key pointsO_LIPosterior parietal cortex (PPC) Glx levels are positively associated with PPC cortical thickness and local gyrification index, likely because differences in cortical microstructure, including dendritic arbour complexity, contributes to both cortical macrostructure and neuro-metabolic traits across development. C_LIO_LIThe PPC Glx:GABA+ ratio is negatively associated with subcortical gray matter volume, while PPC total NAA is positively associated with cerebral white matter volume, suggesting a link between regional neurochemistry and broader brain structure. C_LIO_LIThese findings emphasise the importance of considering more detailed macrostructural characteristics, as well as bulk tissue composition (white matter, gray matter, cerebral spinal fluid), when interpreting MRS-measured metabolite differences. C_LI

neuroscience↗

bioRxiv2024

Ultra-low-field brain MRI morphometry: test-retest reliability and correspondence to high-field MRI

Magnetic resonance imaging (MRI) enables non-invasive monitoring of healthy brain development and disease. Widely used higher field (>1.5 T) MRI systems are associated with high energy and infrastructure requirements, and high costs. Recent ultra-low-field (<0.1T) systems provide a more accessible and cost-effective alternative. However, it remains uncertain whether anatomical ultra-low-field neuroimaging can be used to reliably extract quantitative measures of brain morphometry, and to what extent such measures correspond to high-field MRI. Here we scanned 23 healthy adults aged 20-69 years on two identical 64 mT systems and a 3 T system, using T1w and T2w scans across a range of (64 mT) resolutions. We segmented brain images into 4 global tissue types and 98 local structures, and systematically evaluated between-scanner reliability of 64 mT morphometry and correspondence to 3 T measurements, using correlations of tissue volume and Dice spatial overlap of segmentations. We report high 64 mT reliability and correspondence to 3 T across 64 mT scan contrasts and resolutions, with highest performance shown by combining three T2w scans with low through-plane resolution into a single higher-resolution scan using multi-resolution registration. Larger structures show higher 64 mT reliability and correspondence to 3 T. Finally, we showcase the potential of ultra-low-field MRI for mapping neuroanatomical changes across the lifespan, and monitoring brain structures relevant to neurological disorders. Raw images are publicly available, enabling systematic validation of pre-processing and analysis approaches for ultra-low-field neuroimaging.

neuroscience↗

bioRxiv2024

The developing Human Connectome Project fetal functional MRI release: Methods and data structures

Recent advances in fetal fMRI present a new opportunity for neuroscience to study functional human brain connectivity at the time of its emergence. Progress in the field however has been hampered by the lack of openly available datasets that can be exploited by researchers across disciplines to develop methods that would address the unique challenges associated with imaging and analysing functional brain in utero, such as unconstrained head motion, dynamically evolving geometric distortions, or inherently low signal-to-noise ratio. Here we describe the developing Human Connectome Projects release of the largest open access fetal fMRI dataset to date, containing 275 scans from 255 fetuses and spanning the period of 20.86 to 38.29 post-menstrual weeks. We present a systematic approach to its pre-processing, implementing multi-band soft SENSE reconstruction, dynamic distortion corrections via phase unwrapping method, slice-to-volume reconstruction and a tailored temporal filtering model, with attention to the prominent sources of structured noise in the in utero fMRI. The dataset is accompanied with an advanced registration infrastructure, enabling group-level data fusion, and contains outputs from the main intermediate processing steps. This allows for various levels of data exploration by the imaging and neuroscientific community, starting from the development of robust pipelines for anatomical and temporal corrections to methods for elucidating the development of functional connectivity in utero. By providing a high-quality template for further method development and benchmarking, the release of the dataset will help to advance fetal fMRI to its deserved and timely place at the forefront of the efforts to build a life-long connectome of the human brain.

neuroscience↗

bioRxiv2024

Differential maturation of the brain networks required for the sensory, emotional and cognitive aspects of pain in human newborns

Pain is multidimensional and complex, including sensory-discriminative, affective- motivational, and cognitive-evaluative components. While the concept of pain is learned through life experience, it is not known when and how the brain networks that are required to encode these different dimensions of pain develop. Using the two largest databases of human brain magnetic resonance (MR) images in the world - the developing Human Connectome Project and the Human Connectome Project - we have mapped the development of the neural pathways required for pain perception in the human brain in infants from <32 weeks to 42 weeks postmenstrual age (n = 372), compared to adults (n = 98). Partial correlation analysis of 15 mins resting BOLD signal between all possible pairwise combinations of 12 pain-related regions of interest showed that overall functional connectivity is significantly weaker in 32- week infants compared to adults. However, over the following weeks, significantly different developmental patterns of connectivity emerge in sensory-discriminative, affective- motivational, and cognitive-evaluative pain networks. The first subnetwork to reach adult levels in strength and proportion of connections is the sensory-discriminative subnetwork (34- 36 weeks PMA), followed by the affective-motivational subnetwork (36-38 weeks PMA), while the cognitive-evaluative subnetwork has still not reached adult levels at 42 weeks. This study reveals a previously unknown pattern of postnatal development of connectome subnetworks necessary for mature pain processing. The brain networks that form the infrastructure to encode different components of pain experience, change rapidly in the equivalent of the last gestational trimester but are still immature at the time of normal birth. Newborn neural pathways required for mature pain processing in the brain are incomplete in newborns compared to adults, particularly with respect to the emotional and evaluative aspects of pain. This data suggests that pain-related networks may have distinct periods of vulnerability to untimely noxious procedures during hospitalization, particularly in preterm infants.

neuroscience↗

bioRxiv2024

Aperiodic and Hurst EEG exponents across early human brain development: a systematic review

In electroencephalographic (EEG) data, power-frequency slope exponents (1/f{beta}) can provide non-invasive markers of in vivo neural activity excitation-inhibition (E:I) balance. E:I balance may be altered in neurodevelopmental conditions; hence, understanding how 1/f{beta} evolves across infancy/childhood has implications for developing early assessments/interventions. This systematic review (PROSPERO-ID: CRD42023363294) explored the early maturation (0-26yrs) of resting-state EEG 1/f measures (aperiodic [AE], power law [PLE] and Hurst [HE] exponents), including studies containing [≥]1 1/f measures and [≥]10 typically developing participants. Five databases (including Embase and Scopus) were searched during March 2023. Forty-two studies were identified (Nparticipants=3478). Risk of bias was assessed using the Quality Assessment with Diverse Studies tool. Narrative synthesis of HE data suggests non-stationary EEG activity occurs throughout development. Age-related trends were complex, with rapid decreases in AEs during infancy and heterogenous changes thereafter. Regionally, AE maxima shifted developmentally, potentially reflecting spatial trends in maturing brain connectivity. This work highlights the importance of further characterising the development of 1/f measures to better understand how E:I balance shapes brain and cognitive development.

neuroscience↗

bioRxiv2023

Dynamic changes in subplate and cortical plate microstructure precede the onset of cortical folding in vivo

Cortical gyrification takes place predominantly during the second to third trimester, alongside other fundamental developmental processes, such as the development of white matter connections, lamination of the cortex and formation of neural circuits. The mechanistic biology that drives the formation cortical folding patterns remains an open question in neuroscience. In our previous work, we modelled the in utero diffusion signal to quantify the maturation of microstructure in transient fetal compartments, identifying patterns of change in diffusion metrics that reflect critical neurobiological transitions occurring in the second to third trimester. In this work, we apply the same modelling approach to explore whether microstructural maturation of these compartments is correlated with the process of gyrification. We quantify the relationship between sulcal depth and tissue anisotropy within the cortical plate (CP) and underlying subplate (SP), key transient fetal compartments often implicated in mechanistic hypotheses about the onset of gyrification. Using in utero high angular resolution multi-shell diffusion-weighted imaging (HARDI) from the Developing Human Connectome Project (dHCP), our analysis reveals that the anisotropic, tissue component of the diffusion signal in the SP and CP decreases immediately prior to the formation of sulcal pits in the fetal brain. By back-projecting a map of folded brain regions onto the unfolded brain, we find evidence for cytoarchitectural differences between gyral and sulcal areas in the late second trimester, suggesting that regional variation in the microstructure of transient fetal compartments precedes, and thus may have a mechanistic function, in the onset of cortical folding in the developing human brain.

neuroscience↗

bioRxiv2023

The developmental trajectory of 1H-MRS brain metabolites from childhood to adulthood.

Human brain development is ongoing throughout childhood, with for example myelination of nerve fibres and refinement of synaptic connections continuing until early adulthood. 1H-Magnetic Resonance Spectroscopy (1H-MRS) can be used to quantify the concentrations of endogenous metabolites (e.g., glutamate and {gamma}-aminobutyric acid (GABA)) in the human brain in vivo and so can provide valuable, tractable insight into the biochemical processes that support postnatal neurodevelopment. This can feasibly provide new insight into and aid management of neurodevelopmental disorders by providing chemical markers of atypical development. This study aims to characterize the normative developmental trajectory of various brain metabolites, as measured by 1H-MRS from a midline posterior parietal voxel. We find significant non-linear trajectories for GABA+, Glx, tNAA and tCr concentrations. Glx and GABA+ concentrations steeply decrease across childhood. tNAA concentrations are relatively stable in childhood but gradually decrease from early adulthood, while tCr concentrations increase from childhood to early adulthood. tCho was the only metabolite to have a strictly linear association with age. Trajectories likely reflect fundamental neurodevelopmental processes (including local circuit refinement) which occur from childhood to early adulthood and can be associated with cognitive development; we find GABA+ concentrations significantly positively correlate with recognition memory scores across post-natal development.

neuroscience↗

bioRxiv2023

Gradient organisation of functional connectivity within resting state networks is present from 25 weeks gestation in the human fetal brain

During the third trimester of human gestation, the structure and function of the fetal brain is developing rapidly, laying the foundation for its connectivity framework across the lifespan. During this juncture, resting state functional MRI can be used to identify resting state networks (RSNs) which mature across gestation to resemble canonical RSNs at full term. However, the emergence of finer grain organisation of connectivity within these RSNs in the fetal brain is unknown. Using in-utero resting state fMRI, we performed connectopic mapping analysis to explore the presence of gradients in functional connectivity organisation of 11 cortical RSNs, known as connectopic maps in fetuses aged 25-37 weeks gestation (GW). We hypothesised that, if present, development of connectopic maps would be network specific in the third trimester of gestation, such that this property would be present within the earlier maturing primary sensory and motor networks before those associated with higher association function. In keeping with this, we found smooth connectopic maps in all of the studied RSNs from 25 GW, with the most spatially consistency across gestational age in the primary sensory and motor networks. Voxel-wise permutation testing of the connectopic maps identified local clusters of voxels within networks that significantly covaried with age, specifically in multisensory processing areas, suggesting multisensory processing may be developing during this period. Our analysis shows that functional gradient organisation is already established in the fetal brain and develops throughout gestation, which has strong implications for understanding how cortical organisation subserves the emergence of behaviour in the ensuing period.

neuroscience↗

bioRxiv2022

Neonatal brain dynamic functional connectivity: impact of preterm birth and association with early childhood neurodevelopment

Brain dynamic functional connectivity characterises transient connections between brain regions, changing over time. Features of brain dynamics have been linked to emotion and cognition in adult individuals, and atypical patterns have been associated with neurodevelopmental conditions such as autism. Although reliable functional brain networks have been consistently identified in neonates, little is known about the early development of dynamic functional connectivity. In this study we characterise dynamic functional connectivity with functional magnetic resonance imaging (fMRI) in the first few weeks of postnatal life in term-born (n = 324) and preterm-born (n = 66) individuals. We show that a dynamic landscape of brain connectivity is already established by the time of birth in the human brain, characterised by six transient states of neonatal functional connectivity with changing dynamics through the neonatal period. The pattern of dynamic connectivity is atypical in preterm-born infants, and associated with atypical social, sensory, and repetitive behaviours measured by the Quantitative Checklist for Autism in Toddlers (Q-CHAT) scores at 18 months of age.

neuroscience↗

bioRxiv2022

Spatiotemporal tissue maturation of thalamocortical pathways in the human fetal brain

The development of connectivity between the thalamus and maturing cortex is a fundamental process in the second half of human gestation, establishing the neural circuits that are the basis for several important brain functions. In this study, we acquired high-resolution in utero diffusion MRI from 140 fetuses as part of the Developing Human Connectome Project, to examine the emergence of thalamocortical white matter over the second to third trimester. We delineate developing thalamocortical pathways and parcellate the fetal thalamus according to its cortical connectivity using diffusion tractography. We then quantify microstructural tissue components along the tracts in the fetal compartments that are critical substrates for white matter maturation, such as the subplate and intermediate zone. We identify patterns of change in the diffusion metrics that reflect critical neurobiological transitions occurring in the second to third trimester, such as the disassembly of radial glial scaffolding and the lamination of the cortical plate. These maturational trajectories of MR signal in transient fetal compartments provide a normative reference to complement histological knowledge, facilitating future studies to establish how developmental disruptions in these regions contribute to pathophysiology.

neuroscience↗

bioRxiv2022

Clinical, socio-demographic, and parental correlates of early autism traits

BackgroundAutism traits emerge between the ages of 1 and 2. It is not known if experiences which increase the likelihood of childhood autism are related to early trait emergence, or if other exposures are more important. Identifying factors linked to toddler autism traits in the general population may improve our understanding of the mechanisms underlying atypical neurodevelopment. MethodsClinical, socio-demographic, and parental information was collected at birth from 536 toddlers in London, UK (gestational age at birth, sex, maternal body mass index, age, parental education level, parental first language, parental history of neurodevelopmental disorders) and at 18 months (parent cohabiting status, two measures of social deprivation, three measures of maternal parenting style, and a measure of maternal postnatal depression). General neurodevelopment was assessed with the Bayley Scales of Infant and Toddler Development, 3rd Edition (BSID-III), and autism traits were assessed using the Quantitative Checklist for Autism in Toddlers (Q-CHAT). Multivariable models were used to identify associations between variables and Q-CHAT. A model including BSID-III was used to identify factors associated with Q-CHAT independent of general neurodevelopment. Models were also evaluated addressing variable collinearity with principal component analysis (PCA). ResultsA multivariable model explained 20% of Q-CHAT variance, with four individually significant variables (two measures of parenting style and two measures of socio-economic deprivation). After adding general neurodevelopment into the model 36% of Q-CHAT variance was explained, with three individually significant variables (two measures of parenting style and one measure of language development). After addressing variable collinearity with PCA, parenting style and social deprivation were positively correlated with Q-CHAT score via a single principal component, independently of general neurodevelopment. Neither sex nor family history of autism were associated with Q-CHAT score. LimitationsThe Q-CHAT is parent rated and is therefore a subjective opinion rather than a clinical assessment. We measured Q-CHAT at a single timepoint, and to date no participant has been followed up in later childhood, so we are focused purely on emerging traits rather than clinical autism diagnoses. ConclusionsAutism traits are common at age 18 months, and greater emergence is specifically related to exposure to early life adversity.

neuroscience↗

bioRxiv2022

Neurophysiological basis of hemodynamic responses in the developing human brain before the time of normal birth

Neurovascular coupling that links neural activity to localized increases in blood flow is essential both for brain function and to prevent tissue injury. In the healthy human brain, this underlies an association between the duration of EEG microstates, which represent coordinated and metastable activation of neuronal ensembles, and increases in hemodynamic activity. However, in early human life it is not clear whether neurovascular coupling is functional as the underlying physiological mechanisms may be too immature to effectively support it. Here, we combined MRI compatible robotics with simultaneous EEG and fMRI data acquisition in 13 preterm infants to assess whether the relationship between neural activity and hemodynamic responses is present in this critical period of early life. Passive sensorimotor stimulation elicited both a distinct sequence of four EEG microstates and a significant rise in the blood oxygen level dependent (BOLD) fMRI signal in the left primary sensorimotor cortex. Furthermore, EEG microstate duration was significantly related to BOLD response amplitude. These results suggest that effective neurovascular coupling is present in the human brain even before the normal time of birth and reveal a complex relationship between EEG and fMRI signals underpinned by patterns of activity across distinct neural ensembles.

neuroscience↗