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.
Institute for Nonlinear Science, University of California San Diego, La Jolla, California 92093-0402, USA. tnowotny@ucsd.edu
Thomas
T
Nowotny
Valentin P
VP
Zhigulin
Allan I
AI
Selverston
Henry D I
HD
Abarbanel
Mikhail I
MI
Rabinovich
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