Silicon neurons that burst when primed

Abstract

The authors present a silicon neuron that responds with a high-frequency burst of spikes (> 250Hz) when appropriately primed; otherwise it responds with lower frequency single spikes (< 100Hz). Our model is based upon neurons that relay sensory inputs to the cortex. The bursts (2-6 spikes) are caused by an excitatory calcium channel, designed using circuits that capture the channel's nonlinear dynamics. With sufficient priming, the channel opens quickly and closes slowly when the neuron's voltage increases. Priming the channel requires lowering the neuron's voltage for a sufficient period; thus, inhibitory inputs that can control the cell's response mode. We fabricated 7200 relay neurons on a 11.5mm ² chip in 0.25 μ m CMOS. We plan to use feedback from a cortex chip to prime the relay neurons and thereby realize attention.