Yu Theodore, Cauwenberghs Gert
Electrical and Computer Engineering Department, Jacobs School of Engineering, University of California San Diego, La Jolla, CA 92093, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:3335-8. doi: 10.1109/IEMBS.2009.5333272.
We study synaptic dynamics in a biophysical network of four coupled spiking neurons implemented in an analog VLSI silicon microchip. The four neurons implement a generalized Hodgkin-Huxley model with individually configurable rate-based kinetics of opening and closing of Na+ and K+ ion channels. The twelve synapses implement a rate-based first-order kinetic model of neurotransmitter and receptor dynamics, accounting for NMDA and non-NMDA type chemical synapses. The implemented models on the chip are fully configurable by 384 parameters accounting for conductances, reversal potentials, and pre/post-synaptic voltage-dependence of the channel kinetics. We describe the models and present experimental results from the chip characterizing single neuron dynamics, single synapse dynamics, and multi-neuron network dynamics showing phase-locking behavior as a function of synaptic coupling strength. The 3mm x 3mm microchip consumes 1.29 mW power making it promising for applications including neuromorphic modeling and neural prostheses.
我们在一个由四个耦合的脉冲神经元组成的生物物理网络中研究突触动力学，该网络在模拟VLSI硅微芯片中实现。这四个神经元实现了一个广义的霍奇金-赫胥黎模型，其中Na+和K+离子通道的开启和关闭具有基于速率的可单独配置的动力学。十二个突触实现了一个基于速率的神经递质和受体动力学的一阶动力学模型，考虑了NMDA和非NMDA型化学突触。芯片上实现的模型可通过384个参数完全配置，这些参数涉及电导、反转电位以及通道动力学的突触前/后电压依赖性。我们描述了这些模型，并展示了来自芯片的实验结果，这些结果表征了单个神经元动力学、单个突触动力学以及多神经元网络动力学，显示了锁相行为作为突触耦合强度的函数。这个3mm x 3mm的微芯片功耗为1.29 mW，使其在神经形态建模和神经假体等应用中具有前景。
