Biology subjects

Tokariev, A.

Publications and source records attributed to Tokariev, A..

3 recordsLinked to original sources

bioRxiv2026

Cortical bursts provide spatio-temporal frames for the large-scale phase synchrony emerging across the birth transition

Structural corticocortical connectivity grows rapidly around birth, but how it establishes the large-scale neuronal interactions needed for lifelong neurocognitive performance remains unclear. Using repeated high-density EEG from 233 preterm-born infants recorded at 33-45 weeks postmenstrual age, we characterized the development of three phase-based interaction modes with distinct temporal relationships to cortical bursts: burst-based, burst-framed, and general phase-based connectivity. Burst-framed connectivity was quantified with a novel metric, nested phase-phase correlation. All three modes declined globally with age but differed spatially: burst-based connectivity became more confined, burst-framed connectivity reorganized towards sensorimotor-association connectivity, whereas general phase-based connectivity retained a stable modular organization. General phase-based connectivity was initially concentrated along burst-framed connections, but this coupling weakened with age. Its greater persistence around term age was associated with poorer neurocognitive outcomes, suggesting delayed network maturation. These findings suggest that bursting may transiently scaffold the maturation of large-scale corticocortical phase synchrony across the birth transition.

neuroscience↗

bioRxiv2024

Emergence of a synergistic scaffold in the brains of human infants

The human brain is a complex organ comprising billions of interconnected neurons which enables interaction with both physical and social environments. Neural dynamics of the whole brain go far beyond just the sum of its individual elements; a property known as "synergy". Previously it has been shown that synergy is crucial for many complex brain functions and cognition, however, it remains unknown how and when the large number of discrete neurons evolve into the unified system able to support synergistic interactions. Here we analysed high-density electroencephalography data from late fetal to early postnatal period. We found that the human brain transitions from redundancy-dominated to synergy-dominated system around birth. Frontal regions lead the emergence of a synergistic scaffold comprised of overlapping subsystems, while the integration of sensory areas developed gradually, from occipital to central regions. Strikingly, early developmental trajectories of brain synergy were modulated by environmental enrichment associated with enhanced mother-infant interactions, and the level of synergy near term equivalent age was associated with later neurocognitive development.

neuroscience↗

bioRxiv2021

Phase-based cortical synchrony is affected by prematurity

Inter-areal synchronization by phase-phase correlations (PPC) of cortical oscillations mediates many higher neurocognitive functions, which are often affected by prematurity, a globally prominent neurodevelopmental risk factor. Here, we used electroencephalography (EEG) to examine brain-wide cortical PPC networks at term-equivalent age, comparing human infants after early prematurity to a cohort of healthy controls. We found that prematurity affected these networks in a sleep state-specific manner, and the differences between groups were also frequency-selective, involving brain-wide connections. The strength of synchronization in these networks was predictive of clinical outcomes in the preterm infants. These findings show that prematurity affects PPC networks in a clinically significant manner suggesting early functional biomarkers of later neurodevelopmental compromise to be used in clinical and translational studies after early neonatal adversity.

neuroscience↗