Astrocytes, via excitatory amino-acid transporter type-2 (EAAT2), are the major sink for released glutamate and contribute to set the strength and timing of synaptic inputs. The conditions required for the emergence of Hebbian plasticity from distributed neural activity remain elusive. Here, we investigate the role of EAAT2 in the expression of a major physiologically relevant form of Hebbian l...

Spike-timing-dependent plasticity (STDP), an asymmetric form of Hebbian learning, shows how synaptic strength between neurons changes corresponding to time difference between preand postspikes [1]. It is widely believed that synaptic plasticity can learn and store information of brain, so understanding STDP helps study of the process of learning in the brain. Moreover, hardware implementation o...

Spike-timing dependent plasticity (STDP) is a form of associative synaptic modification which depends on the respective timing of pre- and post-synaptic spikes. The biophysical mechanisms underlying this form of plasticity are currently not known. We present here a biophysical model which captures the characteristics of STDP, such as its frequency dependency, and the effects of spike pair or sp...

We present a simplified phase model for neuronal dynamics with spike timing-dependent plasticity (STDP). For asymmetric, experimentally observed STDP we find multistability: a coexistence of a fully synchronized, a fully desynchronized, and a variety of cluster states in a wide enough range of the parameter space. We show that multistability can occur only for asymmetric STDP, and we study how ...

A fascinating property of the brain is its ability to continuously evolve and adapt to a constantly changing environment. This ability to change over time, called plasticity, is mainly implemented at the level of the connections between neurons (i.e. the synapses). So if we want to understand the ability of the brain to evolve and to store new memories, it is necessary to study the rules that g...

Organization of spatiotemporal pattern of spontaneous activity and its role in coding temporal sequence were investigated in the hippocampal network model. Automatic alteration of synaptic conductances through STDP organized radially propagating burst activities (RPAs) that initiated at local regions and acted as pacemakers in the CA3 region. The frequency of the rhythmic activity converged int...

We study the capacity of Hodgkin-Huxley neuron in a network to change temporarily or permanently their connections and behavior, the so called spike timing-dependent plasticity (STDP), as a function of their synchronous behavior. We consider STDP of excitatory and inhibitory synapses driven by Hebbian rules. We show that the final state of networks evolved by a STDP depend on the initial networ...

Synaptic plasticity is known to depend on the timing of pre and postsynaptic spikes, a.k.a. spike-timing-dependent plasticity (STDP). This implies that outcomes brought about by STDP should be sensitive to the dynamic properties of pre and postsynaptic neuron activity. Furthermore, because the classical model of STDP does not consider the effect of various pre and postsynaptic spike patterns on...

Experimental evidence from a number of different preparations indicates that repeated pairing of pre-and postsynaptic action potentials can lead to long-term Long-term modification of synaptic efficacy can de-Spike timing-dependent plasticity (STDP) forces syn-pend on the timing of pre-and postsynaptic action apses to compete with each other for control of the potentials. In model studies, such...

We examine the conditions under which spike-timing-dependent plasticity (STDP) normalizes post-synaptic 0ring rates. Our simulations show that the rate normalization property of STDP is fragile and small changes in the LTD=LTP ratio or pre-synaptic input rates can lead to high 0ring rates. We propose an adaptive scheme to dynamically control the LTP=LTD ratio. The biophysics of synapses lead us...