The ‘unitary event' method analyzes multiple spike trains to identify neuronal groups whose coherent activity does not conform with full independence. Here we distinguish ‘genuine' coincidences from those due to sub-group correlations. The introduced model describes a neuron's firing as a...

Not only the issue of the dissociation between signal and noise, but also the issue of the possible contributions of noise in the brain information processing has long been a matter of interest. Recently, Harris and Wolpert (Nature, 394:780-784, 1998) proposed a significant new perspective on...

In hippocampal CA1 pyramidal neurons, action potentials are typically initiated in the axon and backpropagate into the dendrites, shaping the integration of synaptic activity and influencing synaptic plasticity. Here we present compartmental models which reveal that a dichotomy in action...

We studied a system of two ‘identical' oscillatory aVLSI neurons with reciprocal inhibitory connections. The system demonstrates different oscillatory behaviors depending on the strength of the inhibitory connections: antiphase, synchronous, phase-shifted, and quasiperiodic oscillations. We...

We analyzed an interaction between the prefrontal cortex (PFC) and the ventral tegmental area (VTA) via computer simulation. Our previous study (Yamashita and Tanaka 2002) shows an inverted-U shaped concentration-dependent effect of dopamine (DA) on the delay-period activity, which has been...

We analyzed an interaction between the prefrontal cortex (PFC) and the ventral tegmental area (VTA) via computer simulation. Our previous study (Yamashita and Tanaka 2002) shows an inverted-U shaped concentration-dependent effect of dopamine (DA) on the delay-period activity, which has been...

The dentate gyrus has physiological and related behavioral properties suggesting that it implements functions within the hippocampus one of which may be associated with sensory pattern recognition. A top-down dentate gyrus model is defined in terms of an idealized Support Vector Machine pattern...

Suppose that a neuron receive two signals masked by random noise. We ask after neuronal transformation whether the masked signals will become more separable or more mixed. We prove that with positive correlations between input singles, the output will be more separable. The critical value at...

Quantal synaptic failures are random, independent events in which the arrival of an action potential fails to release transmitter. Although quantal failures destroy information, we have discovered conditions where such failures enhance learning by a neural network model of the hippocampus. By...

Inhibitory networks play a crucial role in regulating the activity of target neurons: distinct patterns of interneuronal activity and transitions between them influence the excitability of pyramidal cells. Multiple neurons of a recurrently connected interneuron network converging on the...