Networks of living neurons exhibit diverse patterns activity, including oscillations, synchrony, and waves. Recent work in physics has shown yet another mode activity systems composed many nonlinear units interacting locally. For example, avalanches, earthquakes, forest fires all propagate organized into a critical state which event sizes show no characteristic scale are described by power laws. We hypothesized that similar with complex emergent properties could exist networks cortical...

A major goal of neuroscience is to elucidate mechanisms cortical information processing and storage. Previous work from our laboratory (Beggs Plenz, 2003) revealed that propagation local field potentials (LFPs) in circuits could be described by the same equations govern avalanches. Whereas modeling studies suggested these "neuronal avalanches" were optimal for transmission, it was not clear what role they play Work numerous other laboratories has shown structures can generate reproducible...

Relatively recent work has reported that networks of neurons can produce avalanches activity whose sizes follow a power law distribution. This suggests these may be operating near critical point, poised between phase where rapidly dies out and is amplified over time. The hypothesis the electrical neural in brain potentially important, as many simulations suggest information processing functions would optimized at point. hypothesis, however, still controversial. Here we will explain concept...

Recent experimental work has shown that activity in living neural networks can propagate as a critical branching process revisits many metastable states. Neural network theory suggests attracting states could store information, but little is known about how form such Here we use to model actual data and explore the network. When tune parameter point, find are most numerous dynamics not attracting, neutral.

The tasks of neural computation are remarkably diverse. To function optimally, neuronal networks have been hypothesized to operate near a nonequilibrium critical point. However, experimental evidence for dynamics has inconclusive. Here, we show that the cultured cortical critical. We analyze network data collected at individual neuron level using framework phase transitions. Among most striking predictions confirmed is mean temporal profiles avalanches widely varying durations quantitatively...

Multineuron firing patterns are often observed, yet predicted to be rare by models that assume independent firing. To explain these correlated network states, two groups recently applied a second-order maximum entropy model used only observed rates and pairwise interactions as parameters (Schneidman et al., 2006; Shlens 2006). Interestingly, with minimal assumptions they 90–99% of correlations. If generally applicable, this approach could vastly simplify analyses complex networks. However,...

Transfer entropy (TE) is an information-theoretic measure which has received recent attention in neuroscience for its potential to identify effective connectivity between neurons. Calculating TE large ensembles of spiking neurons computationally intensive, and caused most investigators probe neural interactions at only a single time delay message length bin. This problematic, as synaptic delays cortical neurons, example, range from one tens milliseconds. In addition, produce bursts spikes...

The performance of complex networks, like the brain, depends on how effectively their elements communicate. Despite importance communication, it is virtually unknown information transferred in local cortical consisting hundreds closely spaced neurons. To address this, important to record simultaneously from neurons at a spacing that matches typical axonal connection distances, and temporal resolution synaptic delays. We used 512-electrode array (60 μm spacing) spontaneous activity 20 kHz up...

Although relationships between networks of different scales have been observed in macroscopic brain studies, structures neurons are unknown. To address this, we recorded from up to 500 simultaneously slice cultures rodent somatosensory cortex. We then measured directed effective with transfer entropy, previously validated simulated cortical networks. These enabled us evaluate distinctive nonrandom connectivity at 2 scales. 4 main findings. First, the scale 3–6 (clusters), found that high...

Prenatal cannabis exposure (PCE) influences human brain development, but it is challenging to model PCE using animals and current cell culture techniques. Here, we developed a one-stop microfluidic platform assemble cerebral organoids from embryonic stem cells (hESC) investigate the effect of on early development. By incorporating perfusable chambers, air-liquid interface, protocol, this can simplify fabrication procedure produce large number (169 per 3.5 cm × device area) without fusion, as...

Neural systems include interactions that occur across many scales. Two divergent methods for characterizing such have drawn on the physical analysis of critical phenomena and mathematical study information. Inferring criticality in neural has traditionally rested fitting power laws to property distributions "neural avalanches" (contiguous bursts activity), but fractal nature avalanche shapes recently emerged as another signature criticality. On other hand, complexity, an information...

Recent work has shown that functional connectivity among cortical neurons is highly varied, with a small percentage of having many more connections than others. Also, recent theoretical developments now make it possible to quantify how modify information from the they receive. Therefore, investigate modification, or computation, depends on number neuron receives (in-degree) sends out (out-degree). To do this, we recorded simultaneous spiking activity hundreds in cortico-hippocampal slice...

Much evidence seems to suggest the cortex operates near a critical point, yet single set of exponents defining its universality class has not been found. In fact, when are estimated from data, they widely differ across species, individuals same and even over time, or depending on stimulus. Interestingly, these still approximately hold dynamical scaling relation. Here we show that theory quasicriticality, an organizing principle for brain dynamics, can account this paradoxical situation. As...

Activity-dependent self-organization plays an important role in the formation of specific and stereotyped connectivity patterns neural circuits. By combining neuronal cultures, tools with approaches from network neuroscience information theory, we can study how complex topology emerges local interactions. We constructed effective networks using a transfer entropy analysis spike trains recorded rat embryo dissociated hippocampal neuron cultures between 6 35 days vitro to investigate evolves...

Is the brain really operating at a critical point? We study nonequilibrium properties of neural network which models dynamics neocortex and argue for optimal quasicritical on Widom line where correlation length information transmission are optimized. simulate introduce an analytical mean-field approximation, characterize phase transitions, present diagram, shows that in addition to ordered disordered phase, system exhibits ``quasiperiodic'' corresponding synchronous activity simulations, may...

The analysis of neural systems leverages tools from many different fields. Drawing on techniques the study critical phenomena in statistical mechanics, several studies have reported signatures criticality systems, including power-law distributions, shape collapses, and optimized quantities under tuning. Independently, complexity - an information theoretic measure has been introduced effort to quantify strength correlations across multiple scales a system. This represents important tool...

Understanding the detailed circuitry of functioning neuronal networks is one major goals neuroscience. Recent improvements in recording techniques have made it possible to record spiking activity from hundreds neurons simultaneously with sub-millisecond temporal resolution. Here we used a 512-channel multielectrode array system organotypic cultures cortico-hippocampal brain slices mice. To probe network structure, employed wavelet transform cross-correlogram categorize functional...

To understand how neural circuits process information, it is essential to identify the relationship between computation and circuit organization. Rich clubs, highly interconnected sets of neurons, are known propagate a disproportionate amount information within cortical circuits. Here, we test hypothesis that rich clubs also perform computation. do so, recorded spiking activity on average ∼300 well-isolated individual neurons from organotypic cultures. We then constructed weighted, directed...

Whether the brain operates at a critical “tipping” point is long standing scientific question, with evidence from both cellular and systems-scale studies suggesting that does sit in, or near, regime. Neuroimaging of humans in altered states consciousness have prompted suggestion maintenance dynamics necessary for emergence complex cognition, reduced disorganized may be associated deviations criticality. Unfortunately, many cellular-level reporting signs criticality were performed...

The directionality of network information flow dictates how networks process information. A central component processing in both biological and artificial neural is their ability to perform synergistic integration–a type computation. We established previously that integration varies directly with the strength feedforward flow. However, relationships between recurrent feedback remain unknown. To address this, we analyzed spiking activity hundreds neurons organotypic cultures mouse cortex....

Understanding how ensembles of neurons collectively interact will be a key step in developing mechanistic theory cognitive processes. Recent progress multineuron recording and analysis techniques has generated tremendous excitement over the physiology living neural networks. One developments driving this interest is new class models based on principle maximum entropy. Maximum entropy have been reported to account for spatial correlation structure recorded from several different types data....