title: Biophysical synaptic dynamics in an analog VLSI network of Hodgkin-Huxley neurons.
abstract: 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.
authors: Electrical and Computer Engineering Department, Jacobs School of Engineering, University of California San Diego, La Jolla, CA 92093, USA.
authors: Theodore
authors: T
authors: Yu
authors: Gert
authors: G
authors: Cauwenberghs
mesh_terms: D001703:Biophysics / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D007473:Ion Channels / Q000737:chemistry; D007700:Kinetics; D008051:Lipid Bilayers / Q000737:chemistry; D015233:Models, Statistical; D016202:N-Methylaspartate / Q000737:chemistry; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D018377:Neurotransmitter Agents / Q000737:chemistry; D011188:Potassium / Q000737:chemistry; D012044:Regression Analysis; D012825:Silicon / Q000737:chemistry; D012964:Sodium / Q000737:chemistry; D013569:Synapses / Q000378:metabolism / Q000502:physiology*
chemical_list: D007473:Ion Channels; D008051:Lipid Bilayers; D018377:Neurotransmitter Agents; D016202:N-Methylaspartate; D012964:Sodium; D011188:Potassium; D012825:Silicon