How deep is the brain? The shallow brain hypothesis

Nature reviews. Neuroscience, Journal Year: 2023, Volume and Issue: 24(12), P. 778 - 791

Published: Oct. 27, 2023

Language: Английский

---

White-matter degradation and dynamical compensation support age-related functional alterations in human brain

Cerebral Cortex, Journal Year: 2023, Volume and Issue: 33(10), P. 6241 - 6256

Published: Jan. 5, 2023

Abstract Structural connectivity of the brain at different ages is analyzed using diffusion-weighted magnetic resonance imaging (MRI) data. The largest decrease streamlines found in frontal regions and for long inter-hemispheric links. average length tracts also decreases, but clustering unaffected. From functional MRI we identify age-related changes dynamic (dFC) spatial covariation features (FC) links captured by metaconnectivity. They indicate more stable dFC, wider range variance MC, whereas static FC did not show any significant differences with age. We implement individual whole-brain models test several hypotheses mechanisms operation among underlying neural system. demonstrate that fingerprints are only supported if model accounts for: (i) compensation brains overall loss structural (ii) propagation velocity due to myelination. these 2 conditions, it sufficient decompose time-delays as bimodal distribution distinguishes between intra- delays, same working point captures best, produces variability slow time-scales.

Language: Английский

---

The coming decade of digital brain research: A vision for neuroscience at the intersection of technology and computing

Imaging Neuroscience, Journal Year: 2024, Volume and Issue: 2, P. 1 - 35

Published: April 1, 2024

Abstract In recent years, brain research has indisputably entered a new epoch, driven by substantial methodological advances and digitally enabled data integration modelling at multiple scales—from molecules to the whole brain. Major are emerging intersection of neuroscience with technology computing. This science combines high-quality research, across scales, culture multidisciplinary large-scale collaboration, translation into applications. As pioneered in Europe’s Human Brain Project (HBP), systematic approach will be essential for meeting coming decade’s pressing medical technological challenges. The aims this paper to: develop concept decade digital discuss community large, identify points convergence, derive therefrom scientific common goals; provide framework current future development EBRAINS, infrastructure resulting from HBP’s work; inform engage stakeholders, funding organisations institutions regarding research; address transformational potential comprehensive models artificial intelligence, including machine learning deep learning; outline collaborative that integrates reflection, dialogues, societal engagement on ethical opportunities challenges as part research.

Language: Английский

---

Neuronal connected burst cascades bridge macroscale adaptive signatures across arousal states

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Oct. 27, 2023

Abstract The human brain displays a rich repertoire of states that emerge from the microscopic interactions cortical and subcortical neurons. Difficulties inherent within large-scale simultaneous neuronal recording limit our ability to link biophysical processes at microscale emergent macroscopic states. Here we introduce network model layer-5 pyramidal neurons display graded coarse-sampled dynamics matching those observed in macroscale electrophysiological recordings macaques humans. We invert identify spike burst differentiate unconscious, dreaming, awake arousal provide insights into their functional signatures. further show neuromodulatory can mediate different modes around low-dimensional energy landscape, which turn changes response external stimuli. Our results highlight promise multiscale modelling bridge theories consciousness across spatiotemporal scales.

Language: Английский

---

Causal evidence for cholinergic stabilization of attractor landscape dynamics

Cell Reports, Journal Year: 2024, Volume and Issue: 43(6), P. 114359 - 114359

Published: June 1, 2024

There is substantial evidence that neuromodulatory systems critically influence brain state dynamics; however, most work has been purely descriptive. Here, we quantify, using data combining local inactivation of the basal forebrain with simultaneous measurement resting-state fMRI activity in macaque, causal role long-range cholinergic input to stabilization states cerebral cortex. Local nucleus basalis Meynert (nbM) leads a decrease energy barriers required for an transition cortical ongoing activity. Moreover, particular nbM sub-regions predominantly affects information transfer regions known receive direct anatomical projections. We demonstrate these results simple neurodynamical model impact on neuronal firing rates and slow hyperpolarizing adaptation currents. conclude system plays critical stabilizing macroscale dynamics.

Language: Английский

---

Noradrenergic neuromodulation in ageing and disease

Neuroscience & Biobehavioral Reviews, Journal Year: 2023, Volume and Issue: 152, P. 105311 - 105311

Published: July 10, 2023

The locus coeruleus (LC) is a small brainstem structure located in the lower pons and main source of noradrenaline (NA) brain. Via its phasic tonic firing, it modulates cognition autonomic functions involved brain's immune response. extent degeneration to LC healthy ageing remains unclear, however, noradrenergic dysfunction may contribute pathogenesis Alzheimer's (AD) Parkinson's disease (PD). Despite their differences progression at later stages, early involvement lead comparable behavioural symptoms such as preclinical sleep problems neuropsychiatric result AD PD pathology. In this review, we draw attention mechanisms that underlie ageing, PD. We aim motivate future research investigate how system play pivotal role which also be relevant other neurodegenerative diseases.

Language: Английский

---

Mechanisms of vagus nerve stimulation for the treatment of neurodevelopmental disorders: a focus on microglia and neuroinflammation

Frontiers in Neuroscience, Journal Year: 2025, Volume and Issue: 18

Published: Jan. 15, 2025

The vagus nerve (VN) is the primary parasympathetic nerve, providing two-way communication between body and brain through a network of afferent efferent fibers. Evidence suggests that altered VN signaling linked to changes in neuroimmune system, including microglia. Dysfunction microglia, resident innate immune cells brain, associated with various neurodevelopmental disorders, schizophrenia, attention deficit hyperactive disorder (ADHD), autism spectrum (ASD), epilepsy. While mechanistic understanding linking VN, disorders remains incomplete, stimulation (VNS) may provide better VN’s mechanisms act as possible treatment modality. In this review we examine important role modulating system inflammatory reflex, which involves cholinergic anti-inflammatory pathway, releases acetylcholine. Within central nervous (CNS), direct release acetylcholine can also be triggered by VNS. Homeostatic balance CNS notably maintained Microglia facilitate neurogenesis, oligodendrogenesis, astrogenesis, promote neuronal survival via trophic factor release. These monitor microenvironment complex sensome, groups receptors proteins enabling microglia modify health neurochemistry. Given limitations pharmacological interventions for seeks explore application VNS an intervention conditions. Accordingly, established action, e.g., modulation neurotransmitter pathways, well emerging preclinical clinical evidence supporting VNS’s impact on symptoms such those related inflammation induced infections. We discuss potential adapting non-invasive prevention these Overall, intended increase alleviating microglial dysfunction involved ADHD, ASD, Additionally, aim reveal new concepts field could serve understand development therapies disorders.

Language: Английский

---

Hierarchical organization of the forebrain cholinergic system in rats

iScience, Journal Year: 2025, Volume and Issue: 28(3), P. 112001 - 112001

Published: Feb. 12, 2025

The basal forebrain (BF) cholinergic system (BFCS) participates in functions that are global across the brain, such as sleep-wake cycles, but also capacities more behaviorally and anatomically specific, including sensory perception. However, how it orchestrates all diverse local remains to be understood. To uncover underlying organization principles, we combined data from rat brains by tracing projections BF cortical areas analyzed spatial-numerical relations of neurons their targets. dataset revealed algorithmically identified hierarchically organized three principal networks: somatosensory-motor, auditory, visual, defined modality most predominant within them. These clusters could enable BFCS coordinate spatially selective signaling, parallel modulation multiple functionally interconnected yet groups areas. This previously unseen blueprint hierarchy is ready for functional testing.

Language: Английский

---

Gain neuromodulation mediates task-relevant perceptual switches: evidence from pupillometry, fMRI, and RNN Modelling

Published: Feb. 27, 2025

Perceptual updating has been hypothesized to rely on a network reset modulated by bursts of ascending neuromodulatory neurotransmitters, such as noradrenaline, abruptly altering the brain’s susceptibility changing sensory activity. To test this hypothesis at large-scale, we analysed an ambiguous figures task using pupillometry and functional magnetic resonance imaging (fMRI). Behaviourally, qualitative shifts in perceptual interpretation image were associated with peaks pupil diameter, indirect readout phasic tone. We further that stimulus ambiguity drives tone leading heightened neural gain, hastening switches. explore computationally, trained recurrent (RNN) analogous categorisation task, allowing gain change dynamically classification uncertainty. As predicted, higher accelerated switching transiently destabilizing network’s dynamical regime periods maximal leveraged low-dimensional RNN dynamics, develop two novel macroscale predictions: switches should occur brain state velocity flattened egocentric energy landscape. Using fMRI confirmed these predictions, highlighting role system large-scale reconfigurations mediating adaptive updates.

Language: Английский

---

Attention-dependent coupling with forebrain and brainstem neuromodulatory nuclei differs across the lifespan

GeroScience, Journal Year: 2025, Volume and Issue: unknown

Published: March 4, 2025

Attentional states reflect the changing behavioral relevance of stimuli in one's environment, having important consequences for learning and memory. Supporting well-established cortical contributions, attentional are hypothesized to originate from subcortical neuromodulatory nuclei, such as basal forebrain (BF) locus coeruleus (LC), which among first change with aging. Here, we characterized interplay between BF LC nuclei their relation two common afferent targets attention memory, posterior cingulate cortex hippocampus, across adult lifespan. Using an auditory target discrimination task during functional MRI, examined influence salience on task-dependent connectivity younger (19-45 years) older adults (66-86 years). In adults, was largely driven by processing, while associated distractor processing. These patterns reversed adults. This age-dependent pattern generalized nucleus basalis Meynert medial septal subnuclei. Preliminary data middle-aged indicates a transitional stage connectivity. Overall, these results reveal distinct roles systems related potential aging, consistent managing increased behaviorally irrelevant distraction Such prominent differences coupling lifespan suggests they may be drivers widespread changes neurocognitive middle age opportune time intervention.

Language: Английский

---