A conductance-based neuronal network in VLSI for studying the CPR circuit of the crayfish

This paper presents a conductance-based neuronal network in VLSI suitable for studying the caudal photoreceptor (CPR) neuron circuits in the crayfish. By the nullcline approach, the neuron circuit with type-I excitability is designed. The synapse circuit further shares the same schematics with the circuit of ion currents to reduce the design complexity. A full chip containing one CPR neuron, one hair neuron, one inter-neuron, and six synapses is designed with the standard 0.18μm CMOS technology. An analog memory array is also included to store the parameters of the system. By interconnecting two chips to form a complete CPR network of the crayfish, the ability to regenerate a variety of spiking patterns observed in the biological CPR network is examined and discussed.