The emergent properties of the connected brain

Science, Год журнала: 2022, Номер 378(6619), С. 505 - 510

Опубликована: Ноя. 3, 2022

There is more to brain connections than the mere transfer of signals between regions. Behavior and cognition emerge through cortical area interaction. This requires integration local distant areas orchestrated by densely connected networks. Brain determine brain's functional organization. The imaging in living has provided an opportunity identify driving factors behind neurobiology cognition. Connectivity differences species among humans have furthered understanding evolution diverging cognitive profiles. pathologies amplify this variability disconnections and, consequently, disintegration functions. prediction long-term symptoms now preferentially based on disconnections. paradigm shift will reshape our maps challenge current models.

Язык: Английский

---

From fossils to mind

Communications Biology, Год журнала: 2023, Номер 6(1)

Опубликована: Июнь 13, 2023

Fossil endocasts record features of brains from the past: size, shape, vasculature, and gyrification. These data, alongside experimental comparative evidence, are needed to resolve questions about brain energetics, cognitive specializations, developmental plasticity. Through application interdisciplinary techniques fossil record, paleoneurology has been leading major innovations. Neuroimaging is shedding light on organization behaviors. Inferences development physiology extinct species can be experimentally investigated through organoids transgenic models based ancient DNA. Phylogenetic methods integrate data across associate genotypes phenotypes, Meanwhile, archeological discoveries continuously contribute new knowledge. cooperation, scientific community accelerate knowledge acquisition. Sharing digitized museum collections improves availability rare fossils artifacts. Comparative neuroanatomical available online databases, along with tools for their measurement analysis. In context these advances, paleoneurological provides ample opportunity future research. Biomedical ecological sciences benefit paleoneurology's approach understanding mind as well its novel research pipelines that establish connections between neuroanatomy, genes behavior.

Язык: Английский

---

Functional topography of the corpus callosum as revealed by fMRI and behavioural studies of control subjects and patients with callosal resection

Neuropsychologia, Год журнала: 2023, Номер 183, С. 108533 - 108533

Опубликована: Март 9, 2023

The concept of a topographical map the corpus callosum (CC), main interhemispheric commissure, has emerged from human lesion studies and anatomical tracing investigations in other mammals. Over last few years, rising number researchers have been reporting functional magnetic resonance imaging (fMRI) activation also CC. This short review summarizes behavioral performed groups healthy subjects patients undergone to partial or total callosal resection, it is focused on work conducted by authors. Functional data collected diffusion tensor tractography (DTI DTT) (fMRI), both techniques allowing expand refine our knowledge commissure. Neuropsychological test were administered, simple task, as imitation perspective mental rotation ability, analyzed. These researches added new insight topographic organization By combining DTT fMRI was possible observe that crossing points fibers connecting homologous primary sensory cortices, correspond CC sites where elicited peripheral stimulation detected. In addition, during performance reported. demonstrated presence specific fiber tracts cross commissure genu, body, splenium, at showing activation, consistently with cortical activated areas. Altogether, these findings lend further support notion displays organization, related behavior.

Язык: Английский

---

Individual variability in functional connectivity of human auditory cortex

Cerebral Cortex, Год журнала: 2024, Номер 34(2)

Опубликована: Янв. 26, 2024

Abstract Individual variability in functional connectivity underlies individual differences cognition and behaviors, yet its association with specialization the auditory cortex remains elusive. Using resting-state magnetic resonance imaging data from Human Connectome Project, this study was designed to investigate spatial distribution of whole-brain network architecture. An inherent hierarchical axis discerned, which radiates medial lateral orientation, left demonstrating more pronounced variations than right. This exhibited a significant correlation structural metrics cortex. Four subregions, were identified clustering analysis based on variability, unique connectional fingerprints cognitive maps, certain subregions showing specificity speech perception activation. Moreover, lateralization fingerprint U-shaped trajectory across subregions. These findings emphasize role understanding cortical organization, as well revealing activation, connectome, perspectives.

Язык: Английский

---

Cortical mapping of callosal connections in healthy young adults

Human Brain Mapping, Год журнала: 2024, Номер 45(3)

Опубликована: Фев. 15, 2024

The corpus callosum (CC) is the principal white matter bundle supporting communication between two brain hemispheres. Despite its importance, a comprehensive mapping of callosal connections still lacking. Here, we constructed first bidirectional population-based connectional atlas midsagittal section CC and cerebral cortex human by means diffusion-weighted imaging tractography. estimated topographic maps within this have most fine-grained spatial resolution, demonstrate histological validity, were reproducible in independent samples. This new resource, complete atlas, will facilitate investigation interhemispheric come with user-friendly companion online tool (CCmapping) for easy access visualization atlas.

Язык: Английский

---

Reduced lateralization of the language network in the blind and its relationship with white matter tract neuroanatomy

Frontiers in Human Neuroscience, Год журнала: 2024, Номер 18

Опубликована: Авг. 12, 2024

Several previous studies reported reduced leftward lateralization in blind participants' samples compared to the sighted population. The origins of this difference remain unknown. Here, we tested whether functional is connected with structural characteristics white matter tracts [corpus callosum (CC), uncinate fasciculus (UF), and superior longitudinal (SLF)], as suggested by conducted typical Twenty-three 21 adult participants were during fMRI a semantic decision paradigm presented both auditorily modality appropriate for reading (tactually visually sighted). Lateralization indices (LI) calculated based on activations. fractional anisotropy (FA) measure was extracted from interest. Correlation analyses testing relationship between FA LI conducted. speech processing reading-related activations replicated. Nevertheless, integrity CC asymmetry intrahemispheric not confirmed, possibly due lack power. sources language network sensory-deprived population Further should account environmental variables (e.g., frequency contact written language) complexity factors that may influence human brain.

Язык: Английский

---

Exploring Brain Size Asymmetry and Its Relationship with Predation Risk Among Chinese Anurans

Biology, Год журнала: 2025, Номер 14(1), С. 38 - 38

Опубликована: Янв. 7, 2025

Brain size asymmetry differs considerably across species, including humans, vertebrates, and invertebrates. The subtle structural, functional, or differences between the two brain sides are associated with processing specific cognitive tasks. To evaluate sizes of left right whole regions effect predation risk (i.e., snake density) on among Chinese anurans, we compared hemisphere anuran species analyzed correlations index regions. We found that when one side was consistently larger than other, there a significant difference regions, displaying directional also total positively correlated olfactory bulb optic tecta hemispheres were ones. Meanwhile, telencephalon However, non-significant 99 anurans. Our findings suggest an increased linked to sociality is likely drive increase in size.

Язык: Английский

---

Functional divergence between the two cerebral hemispheres contributes to human fluid intelligence

Communications Biology, Год журнала: 2025, Номер 8(1)

Опубликована: Май 17, 2025

Hemispheric lateralization is linked to potential cognitive advantages. It considered a driving force behind the generation of human intelligence. However, establishing quantitative links between degree and intelligence in humans remains elusive. In this study, we propose framework that utilizes functional aligned multidimensional representation space derived from hemispheric gradients compute between-hemisphere distances within space. Applying large cohort (N = 777), identified high divergence across two hemispheres frontoparietal network. We found both global cerebral regional multiple demand network were positively associated with fluid composite score partially mediated relationship brain size individual differences Together, these findings deepen our understanding as fundamental organizational principle brain, providing empirical evidence for its role supporting

Язык: Английский

---

Hemispheric asymmetries and brain size in mammals

Communications Biology, Год журнала: 2023, Номер 6(1)

Опубликована: Май 15, 2023

Hemispheric asymmetries differ considerably across species, but the neurophysiological base of this variation is unclear. It has been suggested that hemispheric evolved to bypass interhemispheric conduction delay when performing time-critical tasks. This implies large brains should be more asymmetric. We performed preregistered cross-species meta-regressions with brain mass and neuron number as predictors for limb preferences, a behavioral marker asymmetries, in mammals. Brain showed positive associations rightward preferences negative leftward preferences. No significant were found ambilaterality. These results are only partly line idea critical factor drives evolution asymmetries. They suggest larger-brained species tend shift towards right-lateralized individuals. Therefore, need coordination lateralized responses social needs considered context

Язык: Английский

---

Difference in axon diameter and myelin thickness between excitatory and inhibitory callosally projecting axons in mice

Cerebral Cortex, Год журнала: 2022, Номер 33(7), С. 4101 - 4115

Опубликована: Авг. 24, 2022

Synchronization of network oscillation in spatially distant cortical areas is essential for normal brain activity. Precision synchronization between hemispheres depends on the axonal conduction velocity, which determined by physical parameters axons involved, including diameter, and extent myelination. To compare these long-projecting excitatory inhibitory corpus callosum, we used genetically modified mice virus tracing to separately label CaMKIIα expressing GABAergic axons. Using electron microscopy analysis, revealed that (i) axon diameters fibers (myelinated axons) are significantly larger than those nonmyelinated axons; (ii) bare myelinated their counterparts; (iii) fibers. Also, thickness myelin ensheathing greater axons, with ultrastructure around also differing. We generated a computational model investigate functional consequences parameter divergences. Our simulations indicate impulses through reach target almost simultaneously, whereas action potentials conducted cells considerable delay.

Язык: Английский

---