Enhancement of synchronization in a hybrid neural circuit by spike-timing dependent plasticity.
Synchronization of neural activity is fundamental for many functions of the brain. We demonstrate that spike-timing dependent plasticity (STDP) enhances synchronization (entrainment) in a hybrid circuit composed of a spike generator, a dynamic clamp emulating an excitatory plastic synapse, and a chemically isolated neuron from the Aplysia abdominal ganglion. Fixed-phase entrainment of the Aplysia neuron to the spike generator is possible for a much wider range of frequency ratios and is more precise and more robust with the plastic synapse than with a nonplastic synapse of comparable strength. Further analysis in a computational model of Hodgkin-Huxley-type neurons reveals the mechanism behind this significant enhancement in synchronization. The experimentally observed STDP plasticity curve appears to be designed to adjust synaptic strength to a value suitable for stable entrainment of the postsynaptic neuron. One functional role of STDP might therefore be to facilitate synchronization or entrainment of nonidentical neurons.
Nowotny
Thomas
T
Institute for Nonlinear Science, University of California San Diego, La Jolla, California 92093-0402, USA. tnowotny@ucsd.edu
Zhigulin
Valentin P
VP
Selverston
Allan I
AI
Abarbanel
Henry D I
HD
Rabinovich
Mikhail I
MI
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D001048:Aplysia; D002469:Cell Separation; D003198:Computer Simulation; D017952:Ganglia, Invertebrate / Q000166:cytology / Q000502:physiology*; D066298:In Vitro Techniques; D008959:Models, Neurological; D009415:Nerve Net / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D015203:Reproducibility of Results; D013997:Time Factors