A5010999791- Neural dynamics and brain function
- Advanced Memory and Neural Computing
- stochastic dynamics and bifurcation
- Visual perception and processing mechanisms
- Photoreceptor and optogenetics research
- Solar and Space Plasma Dynamics
- Advanced Fluorescence Microscopy Techniques
- Neuroscience and Neural Engineering
- Neuroscience and Neuropharmacology Research
- Functional Brain Connectivity Studies
- Neural Networks and Reservoir Computing
- Neurobiology and Insect Physiology Research
- Genetics, Aging, and Longevity in Model Organisms
- Image Processing Techniques and Applications
- Optical measurement and interference techniques
- Nonlinear Dynamics and Pattern Formation
- Circadian rhythm and melatonin
- Neural Networks and Applications
- Ferroelectric and Negative Capacitance Devices
- Cell Image Analysis Techniques
- Blind Source Separation Techniques
- Stellar, planetary, and galactic studies
- Advanced Thermodynamics and Statistical Mechanics
- Adaptive optics and wavefront sensing
- Astro and Planetary Science
Peking University
2016-2025
Institute of Bioinformatics
2021
New Jersey Institute of Technology
2001-2011
New York University
2001-2011
Rensselaer Polytechnic Institute
2011
Courant Institute of Mathematical Sciences
2001-2011
University of Verona
2003
Columbia University
1998-2001
University of Cambridge
1994-1998
Fermi National Accelerator Laboratory
1995
C. elegans neurons were thought to be non-spiking until our recent discovery of action potentials in the sensory neuron AWA; however, extent which nervous system relies on analog or digital coding is unclear. Here we show that enteric motor AVL and DVB fire synchronous all-or-none calcium-mediated following intestinal pacemaker during rhythmic defecation behavior. fires unusual compound with each depolarizing calcium spike mediated by UNC-2 followed a hyperpolarizing potassium...
We explain how simple and complex cells arise in a large-scale neuronal network model of the primary visual cortex macaque. Our consists ≈4,000 integrate-and-fire, conductance-based point neurons, representing small, 1-mm 2 patch an input layer cortex. In local connections are isotropic nonspecific, convergent from lateral geniculate nucleus confers cortical with orientation spatial phase preference. The balance between drive determines whether individual neurons this recurrent circuit or...
A coarse-grained representation of neuronal network dynamics is developed in terms kinetic equations, which are derived by a moment closure, directly from the original large-scale integrate-and-fire (I&F) network. This powerful theory captures full dynamic range networks, mean-driven limit (a such as number neurons N → ∞, fluctuations vanish) to fluctuation-dominated (such small networks). Comparison with numerical simulations I&F establishes that reduced very accurate and...
Efficient processing of information is crucial for the optimization neural resources in both biological and artificial visual systems. In this paper, we study efficiency that may be obtained via use a fovea. Using biologically-motivated agents, processing, learning, decision making controlled environment, namely Atari Pong video game. We compare necessary to play between agents with without Our shows fovea can significantly reduce resources, form number neurons, synapses, computations, while...
We present a detailed theoretical framework for statistical descriptions of neuronal networks and derive (1 + 1)-dimensional kinetic equations, without introducing any new parameters, directly from conductance-based integrate-and-fire networks.We describe the details derivation our equation, proceeding simplest case one excitatory neuron, to coupled purely neurons, consisting both inhibitory neurons.The dimension reduction in theory is achieved via novel moment closures.We also limiting...
Escape is an evolutionarily conserved and essential avoidance response. Considered to be innate, most studies on escape responses focused hard-wired circuits. We report here that a neuropeptide NLP-18 its cholecystokinin receptor CKR-1 enable the circuit execute full omega (Ω) turn. demonstrate in vivo mainly secreted by gustatory sensory neuron (ASI) activate head motor (SMD) turn-initiating interneuron (AIB). Removal of or specific knockdown SMD AIB neurons leads shallower turns, hence...
Abstract The capabilities of natural neural systems have inspired new generations machine learning algorithms as well neuromorphic very large-scale integrated (VLSI) circuits capable fast, low-power information processing. However, it has been argued that most modern are not neurophysiologically plausible. In particular, the workhorse deep learning, backpropagation algorithm, proven difficult to translate hardware. this study, we present a neuromorphic, spiking algorithm based on...
The effect of a strong magnetic field on photospheric convection in cool star like the Sun can be established by relating high-resolution solar observations to results from nonlinear models that rely computation. patterns motion numerical experiments three-dimensional, compressible magnetoconvection depend not only strength imposed vertical but also aspect ratio λ computational box. In wide box (λ=8) with moderately field, flow organizes itself so flux is separated motion. There are regions...
Abstract The optogenetic neuron ablation approach enables noninvasive remote decoding of specific function within a complex living organism in high spatiotemporal resolution. However, it suffers from shallow tissue penetration visible light with low efficiency. This study reports upconversion nanoparticle (UCNP)–based multiplex proteins activation tool to ablate deep‐tissue neurons for locomotion modulation. By optimizing the dopant contents and nanoarchitecure, over 300‐fold enhancement...
Coherent neural spiking and local field potentials are believed to be signatures of the binding transfer information in brain. activity has now been measured experimentally many regions mammalian cortex. Recently experimental evidence presented suggesting that is encoded transferred packets, i.e., stereotypical, correlated patterns activity. Due their relevance coherent spiking, synfire chains one main theoretical constructs have appealed order describe phenomena. However, for some time, it...
The capabilities of natural neural systems have inspired both new generations machine learning algorithms as well neuromorphic, very large-scale integrated circuits capable fast, low-power information processing. However, it has been argued that most modern are not neurophysiologically plausible. In particular, the workhorse deep learning, backpropagation algorithm, proven difficult to translate neuromorphic hardware. This study presents a spiking algorithm based on synfire-gated dynamical...
Within a large-scale neuronal network model of macaque primary visual cortex, we examined how intrinsic dynamic fluctuations in synaptic currents modify the effect strong recurrent excitation on orientation selectivity. Previously, showed that, using inhibition countered by feedforward and excitation, cortical reproduced many observed properties simple complex cells. However, that network's cells were poorly selective for orientation, increasing self-excitation led to instabilities...
Orientation tuning is a fundamental response property of V1 neurons and has been extensively studied with single-/multiunit recording intrinsic signal optical imaging. Long-term 2-photon calcium imaging allows simultaneous hundreds at single neuron resolution over an extended time in awake macaques, which may help elucidate orientation properties greater detail. We used this new technology to study the microstructures functional maps, as well population properties, superficial layers 5...
The ability to map functional connectivity is necessary for the study of flow activity in neuronal circuits. Optical imaging calcium indicators, including FRET-based genetically encoded indicators and extrinsic dyes, an important adjunct electrophysiology widely used visualize activity. However, techniques mapping connectivities with data have been lacking. We present a procedure compute reduced couplings between ensembles undergoing seizure from ratiometric three steps: (1) calculation...
Epigenetic regulation plays an important role in cell migration. Although many methods have been developed to measure the motility of mammalian cells, accurate quantitative assessments migration speed individual cells remain a major challenge. It is difficult for conventional scratch assays differentiate proliferation from during so-called wound-healing processes because long experimental time required. In addition, it also challenging create identical conditions evaluating by methods. We...
Flux expulsion is an important consequence of the interaction magnetic fields with fluid convection and has been well studied for particular cases steady, single-cell flows. Here we examine a related phenomenon in inhomogeneous turbulence using direct numerical simulations. To understand our results, analyse average properties model, obtain mean transport coefficients which can be used to describe approach system its final state. For kinematic problem these give excellent prediction process;...
We analyze phase separation in ternary systems the asymptotic hydrodynamic regime when volume fractions and concentrations are constant. The multiphase Navier-Stokes equations solved using a level set method. A new projection method was developed to treat multiple junctions for with more than two phases. It is found that surface tension ratios can alter growth mechanism of minority presence majority When wets interface phases domain rate all three initially similar symmetric binary fluid but...
The ratio ${R}_{1}$ between the average magnetic energy and square-averaged flux plays an important role in study of nonlinear dynamos, as a measure efficiency dynamo at generating flux. For large values ${R}_{m}$, displays scaling behavior type ${R}_{1}\ensuremath{\sim}{R}_{m}^{n}$, where ${R}_{m}$ is Reynolds number. We show by direct numerical evaluation that $n$ depends sensitively on flow complexity for small-scale dynamos. Furthermore, relating to cancellation exponent correlation...
Steady dynamics of coupled conductance-based integrate-and-fire neuronal networks in the limit small fluctuations is studied via equilibrium states a Fokker-Planck equation. An asymptotic approximation for membrane-potential probability density function derived and corresponding gain curves are found. Validity conditions discussed description verified direct numerical simulations.
Unifying the results obtained from large-scale, physiologically realistic, yet minimal computational primary visual cortex (V1) network models and identifying single cortical operating state, namely, an intermittent desuppressed state (IDS) with fluctuation-controlled criticality are presented. The study suggests a possible of V1 characterised by high total conductance strong inhibition, large synaptic fluctuation, important role played N-methyl-D-aspartic acid in long-range,...