PT - JOURNAL ARTICLE AU - Kenrick Yap AU - Alexander Drakew AU - Dinko Smilovic AU - Michael Rietsche AU - Mario Vuksic AU - Domenico Del Turco AU - Thomas Deller TI - The actin-modulating protein Synaptopodin mediates long-term survival of dendritic spines AID - 10.1101/2020.05.08.080374 DP - 2020 Jan 01 TA - bioRxiv PG - 2020.05.08.080374 4099 - http://biorxiv.org/content/early/2020/05/08/2020.05.08.080374.short 4100 - http://biorxiv.org/content/early/2020/05/08/2020.05.08.080374.full AB - Large spines are stable and important for memory trace formation. The majority of large spines also contains Synaptopodin (SP), an actin-modulating and plasticity-related protein. Since SP stabilizes F-actin, we speculated that the presence of SP within large spines could explain their long lifetime. Indeed, using time-lapse 2-photon-imaging of SP-transgenic granule cells in mouse organotypic tissue cultures we found that spines containing SP survived considerably longer than spines of equal size without SP. Of note, SP-positive spines that underwent pruning first lost SP before disappearing. Whereas the survival time courses of SP-positive (SP+) spines followed conditional two-phase decay functions, SP-negative (SP-) spines and all spines of SP-deficient animals showed single exponential decays. These results implicate SP as a major regulator of long-term spine stability: SP clusters stabilize spines and the presence of SP indicates spines of high stability.Competing Interest StatementThe authors have declared no competing interest.