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.
O'Connor
Daniel H
DH
Department of Molecular Biology and Program in Neuroscience, Princeton University, Princeton, NJ 08544, USA.
Wittenberg
Gayle M
GM
Wang
Samuel S-H
SS
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