Dendritic spine dynamics stabilize synaptic plasticity

Cian O'Donnell (School of Informatics, University of Edinburgh), Matthew Nolan (Centre for Integrative Physiology, University of Edinburgh), Mark van Rossum (School of Informatics, University of Edinburgh)

Long-term synaptic plasticity is believed to underlie learning and memory in the brain. At excitatory synapses, plasticity is mediated by molecular machinery that detects local calcium (Ca2+) signals in small structures called dendritic spines. For unknown reasons, spine size is tightly correlated with synaptic strength. We show theoretically that imperfect coupling between spine size and Ca2+ influx fundamentally alters synaptic stability. If Ca2+ influx is under-compensated, then strong synapses are stabilized and synaptic strength distributions are unimodal. In contrast, over-compensation of Ca2+ influx leads to binary, persistent synaptic strengths with bimodal distributions. We conclude that structural plasticity provides a simple, local and general mechanism that allows dendritic spines to foster both rapid memory formation and persistent memory storage.

Preferred presentation format: Poster
Topic: Computational neuroscience

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