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C Rasche

Publications and source records attributed to C Rasche.

2 recordsLinked to original sources

Silicon synaptic depression.

The recent quantitative description of activity-dependent depression in the synaptic transmission between cortical neurons has lead to many interesting suggestions of possible computational implications. Based on a simple biological model, we have constructed an analog circuit that emulates the properties of short-term depressing synapses. The circuit comprises only seven transistors and two capacitors per synapse, and is able to reproduce computational features of depressing synapses such as the 1/F law, the detection of long intervals of presynaptic silence and the sensitivity to redistribution of presynaptic firing rates. It provides a useful basis for implementing neural networks with dynamical synapses.

Computer Simulation↗

Silicon synaptic conductances.

We have developed compact analog integrated circuits that simulate two synaptic excitatory conductances. A four-transistor circuit captures the dynamics of an excitatory postsynaptic current caused by a real AMPA conductance. A six-transistor circuit simulates the effects of a real voltage-dependent NMDA conductance. The postsynaptic current dynamics are modeled by a current mirror integrator with adjustable gain. The voltage dependence of the silicon NMDA conductance is realized by a differential pair. We show the operation of these silicon synaptic conductances and their integration with the silicon neuron (Mahowald and Douglas, 1991).

Action Potentials↗