Oscillatory activities are widely observed in specific frequency bands of recorded field potentials in different brain regions, and play critical roles in processing neural information. Understanding the structure of these oscillatory activities is essential for understanding the brain function. So far many details remain elusive about their rhythmic structures and how these oscillations are generated. We show that many oscillatory activities in spontaneous cortical-subcortical networks, such as delta, spindle, gamma, high-gamma and sharp wave ripple bands in different brain regions, are genuine chaotic time series which can be reconstructed as chaotic attractors through appropriately selected embedding delay and dimension. The reconstructed attractors are approximated by a simple radial basis function enabling high precision short-term prediction. Simultaneously recorded oscillatory activities in multiple brain regions differ greatly in term of temporal phase and amplitude but can be approximated by the same function. Our results suggest that neural oscillations are produced by deterministic chaotic systems. The occurrence of neural oscillation events is predetermined, and the brain possibly knows when and where the information will be processed and transferred in the future time as a result of the deterministic dynamic.
During sleep, the hippocampus recapitulates neuronal patterns corresponding to behavioral trajectories during previous experiences. This hippocampal replay supports the formation of long-term memories. Yet, whether replay originates within the hippocampal circuitry or is initiated by extrahippocampal inputs is unknown. Here, I review recent findings regarding the organization of neuronal activity upstream to the hippocampus, in the head-direction (HD) and grid cell networks. I argue that hippocampal activity is under the influence of primary spatial signals, which originate from subcortical st…
13 Subcortical band heterotopia (SBH), also known as doublecortex syndrome, is a 14 malformation of cortical development resulting from mutations in the doublecortin gene 15 (DCX). It is characterized by a lack of migration of cortical neurons that accumulate in the 16 white matter forming a heterotopic band. Patients with SBH may present mild to moderate 17 intellectual disability as well as epilepsy. The SBH condition can be modeled in rats by in 18 utero knockdown (KD) of Dcx. The affected cells form an SBH reminiscent of that observed in 19 human patients and the animals develop a chronic …
Transferable conditional brain charts link cortico-subcortical structure to Alzheimer's disease progression
University Hospital Tübingen（蒂宾根大学医院）；Friedrich Schiller University Jena（耶拿弗里德里希·席勒大学）；German Center for Mental Health (DZPG)（德国心理健康中心）；Uppsala University（乌普萨拉大学）；Technische Universität Dresden（德累斯顿工业大学）；University of Tübingen（蒂宾根大学）；McLean Hospital（麦克莱恩医院）；Harvard Medical School（哈佛医学院）；University of Technology Nuremberg（纽伦堡应用技术大学）；University of Oslo（奥斯陆大学）；Oslo University Hospital（奥斯陆大学医院）；Max Planck Institute for Biological Cybernetics（马克斯·普朗克生物物理化学研究所）
Multi-modal neuroimaging projects are advancing our understanding of human brain architecture, function, connectivity using high-quality non-invasive data from many subjects. However, ground truth validation of connectivity using invasive tracers is not feasible in humans. Our NonHuman Primate Neuroimaging & Neuroanatomy Project (NHP_NNP) is an international effort (6 laboratories in 5 countries) to: (i) acquire and analyze high-quality multi-modal brain imaging data of macaque and marmoset monkeys using protocols and methods adapted from the HCP; (ii) acquire quantitative invasive tract-traci…
Cortex and subcortex play distinct roles over learning when cortical memory is limited
Laboratory for Neural Computation and Adaptation（神经计算与适应实验室）；RIKEN Center for Brain Science（脑科学研究中心）；Department of Mathematical Informatics, Graduate School of Information Science and Technology（信息科学与技术研究生院数学信息学系）；The University of Tokyo（东京大学）
How human brain function emerges from structure has intrigued researchers for decades and numerous models have been put forward, yet none of them yields a close structure-function relation. Here we present a resonance model based on neuronal spike timing dependent plasticity (STDP) principle to describe the spontaneous cortical activity by incorporating the dynamic interactions between neuronal populations into a wave equation, which is able to accurately predict the resting brain functional connectivity (FC), including the resting-state networks. Besides, the proposed model provides strong th…
In the study of biological networks, one of the major challenges is to understand the relationships between network structure and dynamics. In this paper, we model in vitro cortical neuronal cultures as stochastic dynamical systems and apply a method that reconstructs directed networks from dynamics [Ching and Tam, Phys. Rev. E 95, 010301(R), 2017] to reveal directed effective connectivity, namely the directed links and synaptic weights, of the neuronal cultures from voltage measurements recorded by a multielectrode array. The effective connectivity so obtained reproduces several features of c…
Cortical circuits are characterized by exquisitely complex connectivity patterns that emerge during development from undifferentiated networks. The development of these circuits is governed by a combination of precise molecular cues that dictate neuronal identity and location along with activity dependent mechanisms that help establish, refine, and maintain neuronal connectivity. Here we ask whether simple plasticity mechanisms can lead to assembling a cortical microcircuit with canonical inter-laminar connectivity, starting from a network with all-to-all connectivity. The target canonical mic…
Maximum Entropy models can be inferred from large data-sets to uncover how collective dynamics emerge from local interactions. Here, such models are employed to investigate neurons recorded by multielectrode arrays in the human and monkey cortex. Taking advantage of the separation of excitatory and inhibitory neuron types, we construct a model including this distinction. This approach allows to shed light upon differences between excitatory and inhibitory activity across different brain states such as wakefulness and deep sleep, in agreement with previous findings. Additionally, Maximum Entrop…
The spontaneous activity pattern of cortical neurons in dissociated culture is characterized by burst firing that is highly synchronized among a wide population of cells. The degree of synchrony, however, is excessively higher than that in cortical tissues. Here, we employed polydimethylsiloxane (PDMS) elastomers to establish a novel system for culturing neurons on a scaffold with an elastic modulus resembling brain tissue, and investigated the effect of the scaffold's elasticity on network activity patterns in cultured rat cortical neurons. Using whole-cell patch clamp to assess the scaffold …
Power spectra of awake resting state EEG recordings in humans typically have an Alpha peak at around 10 Hz riding a decreasing background "Xi process". Normal and pathological variations may have more than one peak or none. The single channel Xi-Alpha model (Pascual-Marqui et al 1988, https://doi.org/10.3109/00207458808985730) separated these two processes, providing a low-dimensional parametric description of EEG spectra. Currently lacking is a generative whole cortex model for activity spectra and intracortical functional connectivity. Here we introduce the "cortical Xi-Alpha model". The cro…
Several experiments and models have highlighted the importance of neuronal heterogeneity in brain dynamics and function. However, how such a cell-to-cell diversity can affect cortical computation, synchronization, and neuronal communication is still under debate. Previous studies have focused on the effect of neuronal heterogeneity in one neuronal population. Here we are specifically interested in the effect of neuronal variability on the phase relations between two populations, which can be related to different cortical communication hypotheses. It has been recently shown that two spiking neu…
Neuronal network models and corresponding computer simulations are invaluable tools to aid the interpretation of the relationship between neuron properties, connectivity and measured activity in cortical tissue. Spatiotemporal patterns of activity propagating across the cortical surface as observed experimentally can for example be described by neuronal network models with layered geometry and distance-dependent connectivity. The interpretation of the resulting stream of multi-modal and multi-dimensional simulation data calls for integrating interactive visualization steps into existing simula…
Cortical network functioning critically depends on finely tuned interactions to afford neuronal activity propagation over long distances while avoiding runaway excitation. This importance is highlighted by the pathological consequences and impaired performance resulting from aberrant network excitability in psychiatric and neurological diseases, such as epilepsy. Theory and experiment suggest that the control of activity propagation by network interactions can be adequately described by a branching process. This hypothesis is partially supported by strong evidence for balanced spatiotemporal d…
In this paper, we review widely used statistical analysis frameworks for data defined along cortical and subcortical surfaces that have been developed in last two decades. The cerebral cortex has the topology of a 2D highly convoluted sheet. For data obtained along curved non-Euclidean surfaces, traditional statistical analysis and smoothing techniques based on the Euclidean metric structure are inefficient. To increase the signal-to-noise ratio (SNR) and to boost the sensitivity of the analysis, it is necessary to smooth out noisy surface data. However, this requires smoothing data on curved …
We examine whether a single biophysical cortical circuit model can explain both spiking and perceptual variability. We consider perceptual rivalry, which provides a window into intrinsic neural processing since neural activity in some brain areas is correlated to the alternating perception rather than the constant ambiguous stimulus. The prevalent theory for spiking variability is a chaotic attractor called the balanced state; whereas, the source of perceptual variability is an open question. We present a dynamical model with a chaotic attractor that explains both spiking and perceptual variab…
Synaptic plasticity and neuron cross-talk are some of the important key mechanisms underlying formation of dynamic clusters of active neurons. The essence of this study is to model and decipher the mechanism of emergence of a task-specific functional connectivity among a population of neurons. We have used our proposed neuron activity pattern (NAP) model to define an assorted range of interactions and simulated across a 2D lattice with two-state (firing/non-firing) neurons. We observed the emergence of scale-free, hierarchically organized ordered patterns of active neurons, that we call as fun…
Graphene has the potential to make a very significant impact on society, with important applications in the biomedical field. The possibility to engineer graphene-based medical devices at the neuronal interface is of particular interest, making it imperative to determine the biocompatibility of graphene materials with neuronal cells. Here we conducted a comprehensive analysis of the effects of chronic and acute exposure of rat primary cortical neurons to few-layers pristine graphene (GR) and monolayer graphene oxide (GO) flakes. By combining a range of cell biology, microscopy, electrophysiolo…
Network algorithmics and the emergence of synchronization in cortical models
当大脑信号被记录在脑电图或一些类似的大规模大脑活动记录中时，通常会观察到振荡模式，这些模式被认为反映了底层神经元集合的总电活动。虽然现在看来，这种模式在时间上与神经元的尖峰和空间上与其他大脑区域都参与了反馈回路，但可能解释这种回路存在的机制基本上仍然未知。在这里，我们提出了一个理论研究，这些问题的皮质模型，我们介绍了较早[内森A，巴博萨VC（2010年）网络算法和皮质突触重量分布的出现。Phys Rev E 81：021916]。我们开始与两个同步措施，旨在捕捉同步的可能性模型提供的整体尖峰活动的神经元和尖峰活动，导致突触后神经元的立即发射的定义。我们目前的计算结果，我们的皮质模型，在Erdens-Rényi意义上的模型是随机的，并在结构上确定性模型。我们已经发现，我们的皮层模型的算法组件最终提供了，通过两个同步措施，在所有情况下，这两种类型的同步出现一个强大的定量基础。反过来，这可以解释神经元组合电活动中的时间反馈回路和空间反馈回路的增加，因为空间上分离的大脑区域参与节奏行为。
We consider the theoretical constraints on interactions between coupled cortical columns. Each column comprises a set of neural populations, where each population is modelled as a neural mass. The existence of semi-stable states within a cortical column has been shown to be dependent on the type of interaction between the constituent neuronal subpopulations, i.e., the form of the implicit synaptic convolution kernels. Current-to-current coupling has been shown, in contrast to potential-to-current coupling, to create semi-stable states within a cortical column. In this analytic and numerical st…
Cortical neural circuits display highly irregular spiking in individual neurons but variably sized collective firing, oscillations and critical avalanches at the population level, all of which have functional importance for information processing. Theoretically, the balance of excitation and inhibition inputs is thought to account for spiking irregularity and critical avalanches may originate from an underlying phase transition. However, the theoretical reconciliation of these multilevel dynamic aspects in neural circuits remains an open question. Herein, we study excitation-inhibition (E-I) b…
