Dendritic spine dynamics leading to spine elimination after repeated inductions of LTD

• Published in: Scientific reports Vol. 5; no. 1; p. 7707
• Main Authors: Hasegawa, Sho, Sakuragi, Shigeo, Tominaga-Yoshino, Keiko, Ogura, Akihiko
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09-01-2015; Nature Publishing Group
• Subjects: 13/106; 14/19; 14/35; 631/378/1595/2167; 631/378/1595/2638; 631/378/2591/2593; 631/378/2597/2599; Animals; Dendritic spines; Dendritic Spines - drug effects; Dendritic Spines - physiology; Fluorescent Dyes - chemistry; Hippocampus - cytology; Hippocampus - drug effects; Hippocampus - physiology; Humanities and Social Sciences; In Vitro Techniques; Long-term potentiation; Long-Term Potentiation - drug effects; Methoxyhydroxyphenylglycol - analogs & derivatives; Methoxyhydroxyphenylglycol - pharmacology; Mice; Mice, Transgenic; Microscopy, Confocal; multidisciplinary; Repetition; Rodents; Science; Spine; Stochasticity; Synapses - physiology; Synaptogenesis; Time Factors
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep07707

Memory is fixed solidly by repetition. However, the cellular mechanism underlying this repetition-dependent memory consolidation/reconsolidation remains unclear. In our previous study using stable slice cultures of the rodent hippocampus, we found long-lasting synaptic enhancement/suppression coupled with synapse formation/elimination after repeated inductions of chemical LTP/LTD, respectively. We proposed these phenomena as useful model systems for analyzing repetition-dependent memory consolidation. Recently, we analyzed the dynamics of dendritic spines during development of the enhancement and found that the spines increased in number following characteristic stochastic processes. The current study investigates spine dynamics during the development of the suppression. We found that the rate of spine retraction increased immediately leaving that of spine generation unaltered. Spine elimination occurred independent of the pre-existing spine density on the dendritic segment. In terms of elimination, mushroom-type spines were not necessarily more stable than stubby-type and thin-type spines.