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bioRxiv · 10.1101/2020.03.16.993675

Altered spike timing-dependent plasticity rules in physiological calcium

Inglebert, Y.·Aljadeff, J.·Brunel, N.·Debanne, D.
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Abstract

Like many forms of long-term synaptic plasticity, spike-timing-dependent plasticity (STDP) depends on intracellular Ca2+ signaling for its induction. Yet, all in vitro studies devoted to STDP used abnormally high external Ca2+ concentration. We measured STDP at the CA3-CA1 hippocampal synapses under different extracellular Ca2+ concentrations and found that the sign, shape and magnitude of plasticity strongly depend on Ca2+. A pre-post protocol that results in robust LTP in high Ca2+, yielded only LTD or no plasticity in the physiological Ca2+ range. LTP could be restored by either increasing the number of post-synaptic spikes or increasing the pairing frequency. A calcium-based plasticity model in which depression and potentiation depend on post-synaptic Ca2+ transients was found to fit quantitatively all the data, provided NMDA receptor-mediated non-linearities were implemented. In conclusion, STDP rule is profoundly altered in physiological Ca2+ but specific activity regimes restore a classical STDP profile.

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Inglebert, Y., Aljadeff, J., Brunel, N., Debanne, D.. 2020-03-17. Altered spike timing-dependent plasticity rules in physiological calcium. https://doi.org/10.1101/2020.03.16.993675

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