Mechanisms of Synaptic Plasticity

Abstract

The changes in synaptic connections among neurons in a network are strongly indicated as a critical mechanism of memory and learning in animals. Experiments over a period of 30 years, but especially in the past five years, have shown clear quantifiable patterns to the way many mammalian neurons change the strength of their connections to others. In particular, when an action potential is induced at one time in the presynaptic cell and at another time in the psotsynaptic cell, the changes in synaptic conductivity depend in a precise way on the time difference between these events. The changes can be positive, called potentiation, or negative, called depression.
We have been developing both phenomenological and biophysical models of the way in which these changes, especially the long term changes, can be induced. Many other laboratories have made detailed investigations of the mechanisms, namely which biochemical pathways are involved, which lead to the long term observed behavior after induction. We have shown that the rules for plasticity dependent on precise spike timing allow two coupled nonlinear periodic oscillators to synchronize over a very wide range of frequencies as the coupling changes with spike timing. This permits such oscillators to work coherently, even in the presence of environmental noise, where a constant coupling would not permit such coherence.

People

R. Huerta
M. I. Rabinovich
T. Nowotny
G. Mindlin
V. Zhigulin
L. Gibb
J. Wolfe
S. Talathi
H. D. I. Abarbanel

Publications

Whitehead, A., M. I. Rabinovich, R. Huerta, V. P. Zhigulin, and H. D. I. Abarbanel, Dynamical Synaptic Plasticity: Experiments and a Model ,
Biological Cybernetics 88: 229-235 (2003)

Abarbanel, H. D. I., R. Huerta, and M. I. Rabinovich, Dynamical Model of long-term synaptic plasticity , Proc. Nat. Acad. Sci, 99, 10132-10237 (2002).

Zhigulin, V. P., M. I. Rabinovich, R. Huerta, and H. D. I. Abarbanel, Robustness and Enhancement of Neural Synchronization by Activity-Dependent Coupling , Physical Review E, 67 021901 (2003).

T. Nowotny, M. I. Rabinovich and H. D. I. Abarbanel Spatial Representation of Temporal Information through spike timing dependent plasticity, Phys. Rev. E 68 (2003) 011908

Abarbanel, H. D. I., L. Gibb, R. Huerta, and M. I. Rabinovich, Biophysical Model of Synaptic Plasticity , to appear in Biological Cybernetics, Spring, 2003.

Nowotny, T., V. P. Zhigulin, A. I. Selverston, H. D. I. Abarbanel, and M. I. Rabinovich, Enhancement of synchronization in a hybrid neural circuit by spike timing dependent plasticity , Journal of Neuroscience, in press.

Comments? Contact
Terry Peters, Phone +1-858-534-7753, tpeters (at) ucsd.edu