Alex D. Reyes

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Correlated spiking is often observed in cortical circuits, but its functional role is controversial. It is believed that correlations are a consequence of shared inputs between nearby neurons and could severely constrain information decoding. Here we show theoretically that recurrent neural networks can generate an asynchronous state characterized by(More)
Populations of neurons in the retina, olfactory system, visual and somatosensory thalamus, and several cortical regions show temporal correlation between the discharge times of their action potentials (spike trains). Correlated firing has been linked to stimulus encoding, attention, stimulus discrimination, and motor behaviour. Nevertheless, the mechanisms(More)
Neurons of the avian nucleus laminaris (NL) provide a neural substrate for azimuthal sound localization. We examined the optimal stimuli for NL neurons to maintain high discharge rates, reliable phase-locking, and sensitivity to time-delayed stimuli. Whole-cell recordings were performed in chick [embryonic days 19-21 (E19-E21)] NL neurons using an in vitro(More)
Neurons of the avian nucleus magnocellularis (NM) relay auditory information from the VIIIth nerve to other parts of the auditory system. To examine the cellular properties that permit NM neurons to transmit reliably the temporal characteristics of the acoustic stimulus, we performed whole-cell recordings in neurons of the chick NM using an in vitro thin(More)
The precise role of synchronous neuronal firing in signal encoding remains unclear. To examine what kinds of signals can be carried by synchrony, I reproduced a multilayer feedforward network of neurons in an in vitro slice preparation of rat cortex using an iterative procedure. When constant and time-varying frequency signals were delivered to the network,(More)
Neuronal firing is determined largely by incoming barrages of excitatory postsynaptic potentials (EPSPs), each of which produce a transient increase in firing probability. To measure the effects of weak transient inputs on firing probability of cortical neurons, we compute phase-response curves (PRCs). PRCs, whose shape can be related to the dynamics of(More)
A fundamental problem in neuroscience is understanding how a neuron transduces synaptic input into action potentials. The dendrites form the substrate for consolidating thousands of synaptic inputs and are the first stage for signal processing in the neuron. Traditionally, dendrites are viewed as passive structures whose main function is to funnel synaptic(More)
It is postulated that synchronous firing of cortical neurons plays an active role in cognitive functions of the brain. An important issue is whether pyramidal neurons in different cortical layers exhibit similar tendencies to synchronise. To address this issue, we performed intracellular and whole-cell recordings of regular-spiking pyramidal neurons in(More)
1. The effects of small, brief depolarizing pulses and excitatory postsynaptic potentials (EPSPs) on neuronal firing were examined in layer V neurons in slices of cat sensorimotor cortex. During intracellular recording, brief depolarizing current pulses (duration, 0.5-2.0 ms; amplitude, 0.1-4.0 nA) were injected in neurons to produce pulse potentials (PPs)(More)