Rubén Moreno

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The effect of a temporally correlated afferent current on the firing rate of a leaky integrate-and-fire neuron is studied. This current is characterized in terms of rates, autocorrelations, and cross correlations, and correlation time scale tau(c) of excitatory and inhibitory inputs. The output rate nu(out) is calculated in the Fokker-Planck formalism in(More)
Early development of mammalian embryos occurs in an environment of relative hypoxia. Nevertheless, human embryonic stem cells (hESC), which are derived from the inner cell mass of blastocyst, are routinely cultured under the same atmospheric conditions (21% O(2)) as somatic cells. We hypothesized that O(2) levels modulate gene expression and differentiation(More)
The impact of synchronous inputs onto a simple neuron model with synapses showing short-term plasticity is studied. The synaptic model includes depression, stochastic release and facilitation. The mean and second-order statistics of the current are computed. The combination of synchrony and STP produces a non-monotonic behavior of the current variance ,(More)
The effect of time correlations in the afferent current on the firing rate of a generalized integrate-and-fire neuron model is studied. When the correlation time τc is small enough the firing rate can be calculated analytically for small values of the correlation amplitude α 2. It is shown that the rate decreases as √ τc from its value at τc = 0. This limit(More)
BACKGROUND Cell culture media conditioned by human foreskin fibroblasts (HFFs) provide a complex supplement of protein and metabolic factors that support in vitro proliferation of human embryonic stem cells (hESCs). However, the conditioning process is variable with different media batches often exhibiting differing capacities to maintain hESCs in culture.(More)
Neurons process their inputs with a variety of synaptic time scales. The presence of fast or slow ÿlters provides the neuron with particular behaviors and changes quantitatively the output rate of the neuron. Here we study the eeect of synapses with arbitrary time constant s on the neuron response and give an analytical prediction of the ÿring rate for(More)
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