Graded bidirectional synaptic plasticity is composed of switch-like unitary events.
Biological information storage events are often rapid transitions between discrete states. In neural systems, the initiation of bidirectional plasticity by all-or-none events may help confer robustness on memory storage. Here, we report that at CA3-CA1 hippocampal synapses, individual potentiation and depression plasticity events are discrete and heterogeneous in nature. Individual synapses began from extreme high and low strength states. Unitary plasticity events were all-or-none and drove synaptic strength between extremes in <1 min. Under naïve conditions, approximately three-fourths of synapses began in a low-strength state. The timing of these unitary events can account for the time course of macroscopic synaptic plasticity.
Department of Molecular Biology and Program in Neuroscience, Princeton University, Princeton, NJ 08544, USA.
Daniel H
DH
O'Connor
Gayle M
GM
Wittenberg
Samuel S-H
SS
Wang
D000818:Animals; D004594:Electrophysiology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology; D006624:Hippocampus / Q000033:anatomy & histology / Q000502:physiology*; D016013:Likelihood Functions; D017774:Long-Term Potentiation / Q000502:physiology; D008568:Memory / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000502:physiology*; D013997:Time Factors