with a single inhibitory neuron connected to a population of excitatory neurons. Each excitatory neuron feeds to this viewpoint, the dynamical equations for the excitatory and inhibitory neurons are similar to gradient descent of further work. 1 Excitatory�inhibitory network Figure 1 depicts ...

Do temporal lobe epilepsy (TLE) seizures in adults promote further seizures? Clinical and experimental data suggest that new synapses are formed after an initial episode of status epilepticus, however their contribution to the transformation of a naive network to an epileptogenic one has been debated. Recent experimental data show that newly formed ...

Professor William Kristan describes difficulties in building excitatory and inhibitory networks, which can either run out of control or remain inactive.

Relatively little is known about the interneurons that constitute the mammalian locomotor central pattern generator and how they interact to produce behavior. A potential avenue of research is to identify genetic markers specific to interneuron populations that will assist further exploration of the role of these cells in the network. One such marker is the EphA4 axon guidance ...

populations: one of excitatory neurons, with membrane potentials Xi, and another of inhibitory neurons Nex excitatory neurons Xi, and Nin inhibitory neu- rons Yj. The inverse of the membrane's time) excitatory (resp., the inhibitory) neurons share

are excitatory neurons and the rest inhibitory. Studying the dynamics of a network of such scale can be done only in two classes: excitatory neurons and inhibitory ones. Although the main difference between them the inhibitory neurons. Similarly, each inhibitory neuron inhibits all the excitatory neurons with a ...

neurons project only excitatory or only inhibitory synapses. This leads to a hidden feedforward representing a pattern of activity across the excitatory (E) and inhibitory (I) neurons in a model network of the dynamics. Because individual neurons project only excitatory or only inhibitory synapses, synaptic

Time Exc. rate The Issues Randomly connected excitatory and inhibitory neurons (often) have a globally of excitatory and in- hibitory neurons with no memories (all the #15; #22; equal to zero) exhibit, over a broad range ... . Coupling is simple: no synapses or dendrites ... What about real, spiking, excitatory and inhibitory

consists of a ring of 32 excitatory neurons that project to a global inhibitory neuron. The inhibitory, from the inhibitory neuron to all excitatory neurons. Black arrows denote exci- tatory connections. The excitatory neurons (empty circles), as well as the inhibitory neuron (filled circle) are implemented using

Alzheimer's disease is the most frequent neurodegenerative disorder and the most common cause of dementia in the elderly. Diverse lines of evidence suggest that amyloid-? (A?) peptides have a causal role in its pathogenesis, but the underlying mechanisms remain uncertain. Here we discuss recent evidence that A? may be part of a mechanism controlling synaptic activity, acting as a positive ...

for their resistance to synchronization.13 Inhibitory and excitatory synapses also play different roles in promoting block for small inhibitory-excitatory networks, such as central pattern generators controlling various discuss also the multistability of inhibitory networks that results in polyrhythmicity of its ...

a network consisting of 2400 excitatory neurons and 1000 inhibitory neurons. The excitatory neurons are con inhibition is setup by con- necting an excitatory neuron to an inhibitory neuron with a probability 0.5 and conductance randomly selected from 0 to 0.1, and connecting an inhibitory neuron to an ...

of neurons with two coupled layers of excitatory and inhibitory neurons can reveal oscillatory activ- ity, & Bastian, 2004) have shown that net- works of neurons with two coupled layers of excitatory and inhibitory an important reason to study networks with excitatory and inhibitory neurons. Based on this ...

... Abstract : A single cell theory for the development of selectivity ... consisting of excitatory and inhibitory cells, both of ... of the evolution of a cell in this ...

... military and naval science, operational warfare ... THE HEALTH SCIENCES BETHESDA MD. ... DISORDERS, ABNORMAL PSYCHOLOGY, PATHOLOGY ...

... When a neuron Page 3. is firing, it emits excitatory and inhibitory signals to the neurons around it. E represents a neuron's ...

of neurons--excitatory and inhibitory. Both types of neurons had single compartments that were modeledGABA by a scaling factor in some simulations. 2.3 Background synaptic input Both excitatory and inhibitory neurons,096 excitatory and 1,024 inhibitory neurons. The excitatory and inhibitory neurons were arranged in ...

a network of integrate-and-fire neurons that receives excitatory or inhibitory spiking input through only excitatory connections to other neu- rons and inhibitory neurons make only inhibitory connections). The inhibitory neurons are driven by the excitatory neurons, and in return they inhibit the ...

. The network possesses NE excitatory neurons and EI NN inhibitory neurons. Connectivity is sparse, == IIE the relative strength of inhibitory and excitatory currents, due to a pattern or pool, affecting a neuron connected networks of excitatory and inhibitory spiking neurons. J Comput ...

connection to one post-synaptic neuron. The network possesses NE excitatory neurons and EI NN inhibitory neurons in a pattern have both excitatory and inhibitory couplings with the rest of the network. One may in the same way as in the Hopfield model, i.e. neurons can have excitatory and ...

Postsynaptic AMPA-type glutamate receptors (AMPARs) mediate most fast excitatory synaptic transmission and are crucial for many aspects of brain function, including learning, memory and cognition. The number, synaptic localization and subunit composition of synaptic AMPARs are tightly regulated by network activity and by the history of activity at ...

GABA by a scaling factor in some simulations. Background synaptic input #12;6 Both excitatory and inhibitory neurons,024 inhibitory neurons. The excitatory and inhibitory neurons were arranged in a two-dimensional space on grids than that of inhibitory neurons. In the regular network topology, each excitatory or ...

- tions and 4 inhibitory neurons (all�to�all bi�directionally con- nected to the excitatory neurons). When) are the inhibitory neurons. Mean activity of the inhibitory neurons activity =200Hz, Mean activity of the excitatory) (bottom) shows the architecture of the soft WTA network used in our chips. The ...

In this paper the problem of signal propagation in networks of excitatory elements is studied. It is found that the geometry of signal transmission paths depends crucially on how an excitatory element responds to a stimulus. Two types of responses are defined: fast and slow. In the slow response case the signal transmission paths are ...

. Cortical circuits are usually modeled as a network of excitatory and inhibitory neurons [9 networks. Empty circles represent excitatory neu- rons. Filled circles represent inhibitory neurons will use r 1 = 3 and r 2 = 11 for excitatory and inhibitory neurons repectively, this values ...

The role of 'noisy' excitation in synchronizing interneuron networks with shunting synapses was studied. The excitatory input was simulated as a Poisson pattern of presynaptic conductance with varying frequencies and amplitudes. We find that higher excitation frequencies induce stronger synchronisation of the network. Within the range ...

The concept of modulating or terminating seizure activity by brain stimulation is attracting considerable attention. The ability of such external excitatory stimuli to terminate repetitive bursting may depend upon identifiable parameters. We investigate the ability of external stimuli to terminate bursting under various conditions in defined neural network ...

in Appendix A. The proportion of excitatory and inhibitory neurons is governed by the neurophysiologically, the number of excitatory neurons is considered to be Nexcit = 0.8N and that of inhibitory neurons is Ninhib - 1) 1 - f . (1) Each neuron in the network (either excitatory or inhibitory) is coupled via Next

(around 20,000 excitatory and 2,000 inhibitory synapses) to a neuron, it was suggested (Shadlen & Newsome The inhibitory and excitatory neurons have identical parameters. We used the SYNOD simulation environment, the neurons receive 4 types of input, 3 of which are local: KI inhibitory synapses, w excitatory synapses

attention through phase relationship of excitatory and inhibitory input synchrony in a model cortical neuron representation of the excitatory and inhibitory synaptic inputs projecting onto the multicompartmental V 4 neuron 2). The V 4 neuron also received continuous uncorrelated background excitatory and inhibitory

neurons and trained links between excitatory and inhibitory neurons. They use inhibition to prevent,e is the weight of the projection of the eth excitatory neuron onto the ith inhibitory neuron with possible values is roughly 0.2. The R- net modeled for this paper has 40% of excitatory neuron pairs linked though at least 1

by the variable h) of the subpopulation of inhibitory neurons that interacts with these excitatory neurons. (These of excitatory and inhibitory neurons are described by the following equations da/dt A a W [a ] H [h ] dh/dt A h of the figure shows the activity in a network of 10 excitatory neurons and 1 inhibitory ...

input to the neurons of the � In cortex, ~80% excitatory cells (pyramidal neurons), ~20% inhibitory by Eugene M. Izhikevich, F % Excitatory neurons Inhibitory ne Ne=800; Ni=200; re=rand(Ne,1); ri=rand(Ni,1) a(h + M � v). (7.11) Neurons are typically classified as either excitatory or inhibitory, meaning

) that there can be many inputs (around 20,000 excitatory and 2000 inhibitory synapses) to a neuron. The inhibitory and excitatory neurons have identical parameters. We used the SYNOD simulation environment, the neurons receive four types of input, three of which are local: KI inhibitory synapses, w excitatory

excitatory and inhibitory neurons cluded. connections between neurons depend spatial separation between e/ i is variable giving temporal evolution of synapse emanating from excitatory/inhibitory neuron inhibitory action. 3. Results network constructed populations neu� 100 excitatory inhibitory. neuron modeled

is due to approximate balance be� tween the inhibitory and excitatory inputs into the cortical neurons� cations? To address these questions we consider a network of NE excitatory and N I inhibitory neurons [5 time it is updated. Excitatory neurons are updated once per time unit, inhibitory units every � time

.Bothlargeandsmallclusterssupportedconstantdensities of excitatory and inhibitory neurons. However, neurons that were provided with more potential partners (larger. As shown in Figure 2I, a similar ratio of excitatory and inhibitory neurons tended to be present across axons Labeling excitatory (E) and inhibitory (I) neurons and ...

) the mean inhibitory input to a neuron cancels the mean excitatory input [8]. BNs of Integrate-and-Fire (IF of randomly chosen inhibitory neurons, a 'shadow' pool, is attached to each excitatory pool in a synfire chain networks of excitatory and inhibitory spiking neurons, J. of Computational Neuroscience, 8(3), ...

point neurons, both excitatory and inhibitory, which represent dynamics in a small patch of 4C � 1 mm2) and inhibitory (I) integrate-and-fire (I&F) neurons, 75% of which are excitatory, and 25% inhibitory, in rough indicated for excitatory (E) and inhibitory (I) cells. The cortical neuron along the ray at angle 2

plausible excitatory and inhibitory neurons, and produces emergent chaotic or- der within the space, inhibitory neurons, or integrate-and-fire excitatory neurons. 2.1. Periodic bursters The periodic bursters and random variation. The output of the periodic bursters is excitatory. 5 #12;2.2. Inhibitory neurons

present the details of our model. It is based on excitatory and inhibitory spiking neurons. The synapses of NE excitatory and NI inhibitory integrate-and-�re neurons. Each neuron in the network is described the different synapses of j 1, �, NE excitatory neurons and of k 1, �, NI inhibitory neurons, with ...

with excitatory synapses,whereas it remains asynchronous with inhibitory synapses (top panels). However neurons excitatory or purely inhibitory neurons display synchronized neural assemblies. * Inhibitory networks (ms) neuronlabel 0 50 100 150 pattern 2 time (ms) 0 50 100 150 pattern 3 time (ms) 2.Excitatory ...

Polymicrogyria is a cerebral cortical malformation characterized by an excessively folded cortical ribbon of miniature and individually thin convolutions. Although polymicrogyria is a highly epileptogenic lesion, its epileptogenic mechanism is unclear. The anomalous cortex associated with polymicrogyria includes less excitable neural tissue such as a cell sparse zone, but involves a part of a ...

Fragile X Syndrome (FXS) is a neurodevelopmental disorder characterized by severe cognitive impairments, sensory hypersensitivity, and comorbidities with autism and epilepsy. Fmr1 knockout (KO) mouse models of FXS exhibit alterations in excitatory and inhibitory neurotransmission, but it is largely unknown how aberrant function of specific neuronal ...

... Excitatory input is received homogeneously from the ganglion neuron's nearest ... However, inhibitory input is received from neurons in the ...

In my laboratory, we work under the premise that neurons individually are not smart at all. Rather, they .... that the collaterals have an inhibitory action ( they hyperpolarize ... When all elements are excitatory, the simulated network ...

... For example, a higher input resistance reduces synaptic shunting, ... input resistance in rat hippocampal granule cells following electrical kindling of ...

... During the contract period, this theory has been ... consisting of excitatory and inhibitory cells, both which ... These two cortical cell types then interact ...

an inhibi- tory link(synapse) which causes an inhibitory effect on the firing of a post-synaptic neuron. A positive weight usually signifies a excitatory ...

An interactive computer simulation package intended for the simulation of neuronal network activity is described. The networks simulated are comprised of excitatory and inhibitory model neurons connected with each other via conventional chemical synapses....

Dynamics of neural spikes, intracellular Ca^2+, and Ca^2+ in intracellular stores was investigated both in isolated Chay's neurons and in the neurons coupled in networks. Three types of neural networks were studied: a purely excitatory neural network, with only excitatory (AMPA) synapses; a ...

of integrate-and-fire excitatory and inhibitory neurons in realistic cortical conditions (before and after-selective flux is purely excitatory, because inhibitory neurons have local axonal ramifications, hence it has with any other neuron (excitatory or inhibitory). Hence each neuron receives on average cNE recurrent

The concept of modulating or terminating seizure activity by brain stimulation is attracting considerable attention. The ability of such external excitatory stimuli to terminate repetitive bursting may depend upon identifiable parameters. We investigate the ability of external stimuli to terminate bursting under various conditions in defined neural network ...

Many constraints on structural and functional cortical network connectivity have been suggested, based on ideas as diverse as minimization of axonal wiring length or volume, minimization of information processing steps, and maximization of complexity. This paper discusses recently suggested roles for static and dynamic network stability in providing ...

Homeostatic synaptic scaling alters the strength of synapses to compensate for prolonged changes in network activity, and involves both excitatory and inhibitory neurons. The immediate-early gene termed Narp (Neuronal activity-regulated pentraxin) encodes a secreted synaptic protein that can bind and cluster AMPA receptors (AMPARs). Here, we report that ...

are these firing patterns generated? Specifically, how do dynamic interactions between excitatory and inhibitory rate. A secondary role is played by network connectivity, which determines whether activity occurs assumptions: excitatory input to a neuron increases its firing rate, inhibitory input decreases it

Information transfer in the brain requires a homeostatic control of neuronal excitability. Therefore, a functional balance between excitatory and inhibitory systems is established during development. This review contains recent information about the molecular mechanisms orchestrating the establishment and maintenance of this excitation-inhibition (E-I) balance, and it reviews ...

a separation of several mm. In addition, the balance of excitatory and inhibitory strength in the passive patch plays a crucial role in its ability to restrain network bursting in the active patch: unexpectedly In our neocortical model we include excitatory and inhibitory neuronal populations, each consisting

Complexity in the temporal organization of neural systems may be a reflection of the diversity of their neural constituents. These constituents, excitatory and inhibitory neurons, comprise a well-defined ratio in vivo and form the substrate for rhythmic oscillatory activity. To begin to elucidate the dynamical implications that underlie this balance, we construct neural ...

The mechanisms that promote excitatory synapse formation and maturation have been extensively studied. However, the molecular events that limit excitatory synapse development so that synapses form at the right time and place and in the correct numbers are less well understood. We have identified a RhoA guanine nucleotide exchange factor, Ephexin5, which ...

We consider biological neural networks of pyramidal cells in a quasistatic approximation. We argue that they can be treated as a coupled map lattice of inhibitory and excitatory site maps, where both maps are derived from perturbation response of rat neocortical pyramidal cells. Inhibitory site maps generate chaotic spike patterns on an open parameter set ...

A Lyapunov function for excitatory-inhibitory networks is constructed. The construction assumes symmetric interactions within excitatory and inhibitory populations of neurons, and antisymmetric interactions between populations. The Lyapunov function yields sufficient conditions for the global asymptotic stability of fixed points. If ...

Neurons in the cortex of behaving animals show temporally irregular spiking patterns. The origin of this irregularity and its implications for neural processing, are unknown. In this paper the hypothesis that the temporal variability in the firing of a neuron results from an approximate balance between its excitatory and inhibitory inputs is investigated theoretically. It ...

Neocortical oscillations result from synchronized activity of a synaptically coupled network and can be strongly influenced by the intrinsic firing properties of individual neurons. As such, the intrinsic electroresponsive properties of individual neurons may have important implications for overall network function. Rhythmic intrinsic bursting (rIB) ...

the particular role of inhibitory interneurons in the control of the E/I balance of layer 5 pyramidal neurons in a functional range. This phenomenon depends on close interactions between excitatory and inhibitory circuits/3 induces parallel potentiation of excitatory and inhibitory inputs on layer 5 pyramidal neurons, leading

Neurons are usually thought of as receiving information primarily through excitatory inputs, with inhibitory inputs playing only a regulating role. According to this view, the fact that a neuron res faster usually means it is receiving increased excitatory input. We here demonstrate, theoretically and numerically, that increasing the strength of inhibitory ...

To examine the role of 5-HT2 receptors in the central cardiorespiratory network, and in particular the respiratory modulation of parasympathetic activity to the heart, we used an in vitro medullary slice that allowed simultaneous examination of rhythmic inspiratory-related activity recorded from hypoglossal rootlet and excitatory inspiratory-related ...

Major Depressive Disorder (MDD) has been conceptualized as a neural network-level disease. Few studies of the neural bases of depression, however, have used analytical techniques that are capable of testing network-level hypotheses of neural dysfunction in this disorder. Moreover, of those that have, fewer still have attempted to determine the ...

We study a network of m identical excitatory cells projecting excitatory synaptic connections onto a single inhibitory interneuron, which is reciprocally coupled to all excitatory cells through inhibitory synapses possessing short-term synaptic depression. We find that such a network with ...

: the cause for absent EAAT2, a glutamate transporter, in amyotrophic lateral sclerosis. Neuron 20 by the brain and spinal cord in amyotrophic lateral sclerosis. N Engl J Med 326:1464�1468. Rothstein JD, Martin) Selective loss of glial glutamate transporter GLT-1 in amyotrophic lateral sclerosis. Ann Neurol 38

Inspired by recent studies regarding dendritic computation, we constructed a recurrent neural network model incorporating dendritic lateral inhibition. Our model consists of an input layer and a neuron layer that includes excitatory cells and an inhibitory cell; this inhibitory cell is activated by the pooled activities of all the ...

Homeostatic plasticity ensures that appropriate levels of activity are maintained through compensatory adjustments in synaptic strength and cellular excitability. For instance, excitatory glutamatergic synapses are strengthened following activity blockade and weakened following increases in spiking activity. This form of plasticity has been described in a wide array of ...

The dynamics of networks of sparsely connected excitatory and inhibitory integrateand -re neurons is studied analytically. The analysis reveals a very rich repertoire of states, including: Synchronous states in which neurons re regularly; Asynchronous states with stationary global activity and very irregular individual cell activity; States in which the ...

Spatiotemporal pattern formation in neuronal networks depends on the interplay between cellular and network synchronization properties. The neuronal phase response curve (PRC) is an experimentally obtainable measure that characterizes the cellular response to small perturbations, and can serve as an indicator of cellular propensity for synchronization. Two ...

The balance between excitatory and inhibitory synapses is crucial for normal brain function. Wnt proteins stimulate synapse formation by increasing synaptic assembly. However, it is unclear whether Wnt signaling differentially regulates the formation of excitatory and inhibitory synapses. Here, we demonstrate that Wnt7a preferentially stimulates ...

The balance between excitatory and inhibitory synapses is crucial for normal brain function. Wnt proteins stimulate synapse formation by increasing synaptic assembly. However, it is unclear whether Wnt signaling differentially regulates the formation of excitatory and inhibitory synapses. Here, we demonstrate that Wnt7a preferentially stimulates ...

is that information is carried in such a system solely through the firing rate of the neurons (Shadlen and Newsome of activity spontaneously? Shadlen and Newsome (1994) developed a model to demon- strate the feasibility for spike firing and generate random firing in the output neurons. Shadlen and Newsome claim

The behavior of an attractor neural network is analyzed. It exhibits low mean temporal activity levels, despite the fact that the intrinsic neuronal cycle time is very short (2 to 3 ms). An effective model, which describes the interplay of excitation and ...

Large sparse circuits of spiking neurons exhibit a balanced state of highly irregular activity under a wide range of conditions. It occurs likewise in sparsely connected random networks that receive excitatory external inputs and recurrent inhibition as well as in networks with mixed recurrent inhibition and excitation. Here we ...

function , chosen because its odd symmetry about zero allows both excitatory and inhibitory outputs from a single neuron. One problem in implementing the ...

I discuss the construction of models that describe the firing rates of excitatory and inhibitory neurons in biological neural networks. A model is presented that incorporates both slow linear and fast nonlinear inhibition. With the appropriate excitatory-to-excitatory couplings this model can act as an associative memory in which ...

Two ideas appear frequently in theories of star formation and galaxy evolution: (1) star formation is nonlocally excitatory, stimulating star formation in neighboring regions by propagation of a dense fragmenting shell or the compression of preexisting cl...

We study the role of network architecture in the formation of synchronous clusters in synaptically coupled networks of bursting neurons. We give a simple combinatorial algorithm that finds the largest synchronous clusters from the network topology. We demonstrate that networks with a certain degree of internal ...

Synaptic connections are known to change dynamically. High-frequency presynaptic inputs induce decrease of synaptic weights. This process is known as short-term synaptic depression. The synaptic depression controls a gain for presynaptic inputs. However, it remains a controversial issue what are functional roles of this gain control. We propose a new hypothesis that one of the functional roles is ...

The mechanisms involved in respiratory rhythm and in its persistence along lifetime have not been completely elucidated yet. The debate if they rely on pacemaker units or on the emerging properties of neural networks is still on. We propose a simple model taking advantage of the synaptic noise and allowing to bridge network and pacemaker theories. The pBC ...

Excitatory-inhibitory networks arise in many regions throughout the central nervous system and display complex spatiotemporal firing patterns. These neuronal activity patterns (of individual neurons and/or the whole network) are closely related to the functional status of the system and differ between normal and pathological states. ...

In this work, we use a complex network approach to investigate how a neural network structure changes under synaptic plasticity. In particular, we consider a network of conductance-based, single-compartment integrate-and-fire excitatory and inhibitory neurons. Initially the neurons are connected randomly with ...

... Stress Response Network in Normal Cells That is ... other aberrations, especially in developing cancer cells. ... genes) into ovarian cancer cell lines that ...

Dr. Giubellino research has focused on cancer biomarkers and on pre-clinical drug development, specifically targeting aberrant protein signaling networks associated with cancer as a new therapeutic strategy.

Neuronal network models often assume a fixed probability of connection between neurons. This assumption leads to random networks with binomial in-degree and out-degree distributions which are relatively narrow. Here I study the effect of broad degree distributions on network dynamics by interpolating between a binomial and a truncated ...

We demonstrate deterministic extensive chaos in the dynamics of large sparse networks of theta neurons in the balanced state. The analysis is based on numerically exact calculations of the full spectrum of Lyapunov exponents, the entropy production rate, and the attractor dimension. Extensive chaos is found in inhibitory networks and becomes more intense ...

In this paper we propose modifications for the learning rules of Marshall's EXIN (excitatory + inhibitory) neural network model in order to decrease its computational complexity and understand the role of the weight updating learning rules in correctly encoding familiar, superimposed and ambiguous input patterns. The MEXIN (Modified EXIN) models introduce ...

Various types of spatiotemporal behavior are described for two-dimensional networks of excitatory and inhibitory neurons with time delayed interactions. It is described how the network behaves as several structural parameters are varied, such as the number of neurons, the connectivity, and the values of synaptic weights. A transition ...

In a variety of vertebrates, including turtle, many classical and contemporary studies of spinal cord neuronal networks generating rhythmic motor behaviors emphasize a Reciprocal Model with alternation of agonists and antagonists, alternation of excitatory and inhibitory postsynaptic potentials, and reciprocal inhibition. Some studies of spinal cord ...

Neural networks consisting of globally coupled excitatory and inhibitory non-identical neurons may exhibit a complex dynamic behavior including synchronization, multi-clustered solutions in phase space and oscillator death. We investigate the conditions under which these behaviors occur in a multidimensional parametric space defined by the connectivity ...

Neural networks consisting of globally coupled excitatory and inhibitory nonidentical neurons may exhibit a complex dynamic behavior including synchronization, multiclustered solutions in phase space, and oscillator death. We investigate the conditions under which these behaviors occur in a multidimensional parametric space defined by the connectivity ...

We investigate bifurcations in neuronal networks with a hub structure. It is known that hubs play a leading role in characterizing the network dynamical behavior. However, the dynamics of hubs or star-coupled systems is not well understood. Here, we study rather subnetworks with a star-like configuration. This coupled system is an important motif in ...

Increased brain size is common in children with autism spectrum disorders. Here we propose that an increased number of cortical excitatory neurons may underlie the increased brain volume, minicolumn pathology and excessive network excitability, leading to sensory hyper-reactivity and seizures, which are often found in autism. We suggest that Fibroblast ...

Increased brain size is common in children with autism spectrum disorders. Here we propose that an increased number of cortical excitatory neurons may underlie the increased brain volume, minicolumn pathology and excessive network excitability, leading to sensory hyper-reactivity and seizures, which are often found in autism. We suggest that Fibroblast ...

A system consisting of two map-based neurons coupled through reciprocal excitatory or inhibitory chemical synapses is discussed. After a brief explanation of the basic mechanism behind generation and synchronization of bursts, parameter space is explored to determine less obvious but biologically meaningful regimes and effects. Among them, we show how ...

A system consisting of two map-based neurons coupled through reciprocal excitatory or inhibitory chemical synapses is discussed. After a brief explanation of the basic mechanism behind generation and synchronization of bursts, parameter space is explored to determine less obvious but biologically meaningful regimes and effects. Among them, we show how ...

Neuronal activity regulates the development and maturation of excitatory and inhibitory synapses in the mammalian brain. Several recent studies have identified signalling networks within neurons that control excitatory synapse development. However, less is known about the molecular mechanisms that regulate the activity-dependent ...

Animals move over a range of speeds by using rhythmic networks of neurons located in the spinal cord. Here we use electrophysiology and in vivo imaging in larval zebrafish (Danio rerio) to reveal a systematic relationship between the location of a spinal neuron and the minimal swimming frequency at which the neuron is active. Ventral motor neurons and ...

Dendritic spines are the sites of the majority of excitatory connections within the brain, and form the post-synaptic compartment of synapses. These structures are rich in actin and have been shown to be highly dynamic. In response to classical Hebbian plasticity as well as neuromodulatory signals, dendritic spines can change shape and number, which is thought to be critical ...

In this paper we present an oscillatory neural network composed of two coupled neural oscillators of the Wilson-Cowan type. Each of the oscillators describes the dynamics of average activities of excitatory and inhibitory populations of neurons. The network serves as a model for several possible network ...

Complex activity in biological neuronal networks can be represented as a sequential transition between complicated metastable states. From a dynamical systems theory point of view sequential activity in neuronal networks is associated with the existence of stable heteroclinic contours in the phase space of the corresponding neuronal model. Previously, the ...

Prophylaxis of posttraumatic epilepsy will require a detailed knowledge of the epileptogenic pathophysiological processes that follow brain injury. Results from studies of experimental models and human epilepsy highlight alterations in GABAergic interneurons and formation of excessive new excitatory synaptic connectivity as prominent targets for prophylactic therapies. ...

in vitro. In vivo the kernel is embedded in a larger network that interacts with the kernel via inhibitory of inhibitory interneurons as an emergent property of network synaptic interac- tions, or from excitatory- spiratory pattern in the adult in vivo (Ramirez et al., 1998; St.-John, 1998). A fundamental role of the pre

We study living neural networks by measuring the neurons� response to a global electrical stimulation. Neural connectivity is lowered by reducing the synaptic strength, chemically blocking neurotransmitter receptors. We use a graph-theoretic approach to show that the connectivity undergoes a percolation transition. This occurs as the giant component disintegrates, ...

, etc.). We consider the networks composed of two interactive populations of excitatory and inhibitory are possible even in the case of very sparse and randomly distributed inhibitory connections and high�/Hopf and saddle-node-on-limit-cycle bifurcations in dynamical systems. The role of oscillatory dynamics

The hippocampus has the capacity for reactivating recently acquired memories and it is hypothesized that one of the functions of sleep reactivation is the facilitation of consolidation of novel memory traces. The dynamic and network processes underlying such a reactivation remain, however, unknown. We show that such a reactivation characterized by local, self-sustained ...

The hippocampus has the capacity for reactivating recently acquired memories and it is hypothesized that one of the functions of sleep reactivation is the facilitation of consolidation of novel memory traces. The dynamic and network processes underlying such a reactivation remain, however, unknown. We show that such a reactivation characterized by local, self-sustained ...

Neuronal network behavior results from a combination of the dynamics of individual neurons and the connectivity of the network that links them together. We study a simplified model, based on the proposal of Feldman and Del Negro (FDN) [Nat. Rev. Neurosci. 7, 232 (2006)]10.1038/nrn1871, of the preB�tzinger Complex, a small neuronal ...

The highly interconnected local and large-scale networks of the neocortical sheet rapidly and dynamically modulate their functional connectivity according to behavioral demands. This basic operating principle of the neocortex is mediated by the continuously changing flow of excitatory and inhibitory synaptic barrages that not only control participation of ...

We study the emergence of polyrhythmic dynamics of motifs which are the building block for small inhibitory-excitatory networks, such as central pattern generators controlling various locomotive behaviors of animals. We discover that the pacemaker determining the specific rhythm of such a network composed of realistic ...

We study the emergence of polyrhythmic dynamics of motifs which are the building block for small inhibitory-excitatory networks, such as central pattern generators controlling various locomotive behaviors of animals. We discover that the pacemaker determining the specific rhythm of such a network composed of realistic ...

We introduced a two-layer network model for the study of the immunization dynamics in epidemics. Spreading of an epidemic is modeled as an excitatory process in a Watts Strogatz small-world network (infection layer) while immunization by prevention of the disease as a dynamic process in a Barab�si Albert scale-free ...

Cortical neuronal activity depends on a balance between excitatory and inhibitory influences. Culturing of neurons on multi-electrode arrays (MEAs) has provided insight into the development and maintenance of neuronal networks. Herein, we seeded MEAs with murine embryonic cortical/hippocampal neurons at different densities (<150 or >1000 cells mm?2) ...

During postnatal development, altered sensory experience triggers the rapid reorganization of neuronal responses and connections in sensory neocortex. This experience-dependent plasticity is disrupted by reductions of intracortical inhibition. Little is known about how the responses of inhibitory cells themselves change during plasticity. We investigated the time course of inhibitory cell ...

Feedback circuitry with conduction and synaptic delays is ubiquitous in the nervous system. Yet the effects of delayed feedback on sensory processing of natural signals are poorly understood. This study explores the consequences of delayed excitatory and inhibitory feedback inputs on the processing of sensory information. We show, through numerical simulations and theory, that ...

A suprathreshold pulse of transcranial magnetic stimulation (TMS) delivered to human motor cortex results in a period of long-interval intracortical inhibition (LICI) followed by a briefer period of disinhibition (late cortical disinhibition [LCD]). Short-interval intracortical facilitation (SICF) is mediated by excitatory networks in the motor cortex ...

The cortical networks show a collective activity of alternating active and silent states known as up and down states during slow wave sleep or anesthesia. The mechanism of this spontaneous activity as well as the anesthesia or sleep are still not clear. Here, using a mean field approach, we present a simple model to study the spontaneous activity of a homogenous cortical ...

We study the phenomenon of spatial coherence resonance (SCR) on Hodgkin-Huxley (HH) neuronal networks that are characterized with information transmission delay. In particular, we examine the ability of additive Gaussian noise to optimally extract a particular spatial frequency of excitatory waves in diffusive and small-world networks ...

In this paper, we study the self-sustained irregular firing activity in 2-D small-world (SW) neural networks consisting of both excitatory and inhibitory neurons by computational modeling. For a proper proportion of unidirectional shortcuts, the stable self-sustained activity with irregular firing states indeed occurs in the considered ...

SummaryElectrical synapses between interneurons contribute to synchronized firing and network oscillations in the brain. However, little is known about how such networks respond to excitatory synaptic input. To investigate this, we studied electrically coupled Golgi cells (GoC) in the cerebellar input layer. We show with ...

The science of large-scale brain networks offers a powerful paradigm for investigating cognitive and affective dysfunction in psychiatric and neurological disorders. This review examines recent conceptual and methodological developments which are contributing to a paradigm shift in the study of psychopathology. I summarize methods for characterizing ...