The fate of hippocampal synapses depends on the sequence of plasticity-inducing events
Abstract
Synapses change their strength in response to specific activity patterns. This functional plasticity is assumed to be the brain's primary mechanism for information storage. We used optogenetic stimulation of rat hippocampal slice cultures to induce long-term potentiation (LTP), long-term depression (LTD), or both forms of plasticity in sequence. Two-photon imaging of spine calcium signals allowed us to identify stimulated synapses and to follow their fate for the next 7 days. We found that plasticity-inducing protocols affected the synapse's chance for survival: LTP increased synaptic stability, LTD destabilized synapses, and the effect of the last stimulation protocol was dominant over earlier stimulations. Interestingly, most potentiated synapses were resistant to depression-inducing protocols delivered 24 hours later. Our findings suggest that activity-dependent changes in the transmission strength of individual synapses are transient, but have long-lasting consequences for synaptic lifetime.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting files. Source data files have been provided for Figures 2, 3, 4 and 5.
Article and author information
Author details
Funding
Deutsche Forschungsgemeinschaft (FOR 2419)
- Thomas G. Oertner
Deutsche Forschungsgemeinschaft (SFB 936 / B7)
- Thomas G. Oertner
Deutsche Forschungsgemeinschaft (SPP 1665)
- Thomas G. Oertner
European Commission (ERC-2016-StG 714762)
- J Simon Wiegert
Deutsche Forschungsgemeinschaft (SPP 1926)
- J Simon Wiegert
Deutsche Forschungsgemeinschaft (FOR 2419)
- J Simon Wiegert
Deutsche Forschungsgemeinschaft (FOR 2419)
- Christine Elizabeth Gee
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: Animal procedures were in accordance with the guidelines of local authorities and Directive 2010/63/EU.
Copyright
© 2018, Wiegert et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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