In this episode of the Epigenetics Podcast, we talked with Tomohisa Toda from the Max-Planck-Zentrum für Physik und Medizin about his work on the long-term maintenance of neuronal identity, with a focus on epigenetic and RNA-based mechanisms in brain stability and aging.Dr. Toda describes how brain circuits are stabilized over time, why critical periods are temporally restricted, and how epigenetic regulation may help maintain established neural identity. This led him to postdoctoral work on neural stem cells and long-term maintenance.We cover his work on nuclear pore and nuclear lamina proteins, including NUP153 and Lamin B1. He explains that NUP153 is enriched in neural stem cells and appears to act as a platform for recruiting factors that help maintain the stem cell epigenome. For Lamin B1, we discuss its decline during aging, how its loss can lead to stem cell exhaustion, reduced adult neurogenesis, and age-related mood dysregulation in the hippocampus.We also discuss LINE-1 RNA, where we learn that reducing LINE-1 promotes neural progenitor differentiation. He explains that this effect is linked to the RNA sequence itself rather than retrotransposition, based on rescue experiments.Finally, we talk about his finding that a subset of postnatally born brain cells contains nuclear RNAs that remain detectable for up to two years. He describes their nuclear enrichment, possible association with heterochromatin, and ongoing work to understand their sequence features, modifications, and biological function.ReferencesBedrosian, T. A., Houtman, J., Eguiguren, J. S., Ghassemzadeh, S., Rund, N., Novaresi, N. M., Hu, L., Parylak, S. L., Denli, A. M., Randolph-Moore, L., Namba, T., Gage, F. H., & Toda, T. (2021). Lamin B1 decline underlies age-related loss of adult hippocampal neurogenesis. The EMBO journal, 40(3), e105819. https://doi.org/10.15252/embj.2020105819Zocher, S., McCloskey, A., Karasinsky, A., Schulte, R., Friedrich, U., Lesche, M., Rund, N., Gage, F. H., Hetzer, M. W., & Toda, T. (2024). Lifelong persistence of nuclear RNAs in the mouse brain. Science (New York, N.Y.), 384(6691), 53–59. https://doi.org/10.1126/science.adf3481Zhilina, D., Bolaños Castro, L. A., Eguiguren, J. S., Zocher, S., Karasinsky, A., Widmer, D., Espinós, A., Borrell, V., Brand, M., Miura, K., Zierau, O., Yun, M. H., & Toda, T. (2026). Dynamic expression of lamin B1 during adult neurogenesis in the vertebrate brain. Developmental dynamics : an official publication of the American Association of Anatomists, 255(2), 187–208. https://doi.org/10.1002/dvdy.70023Related EpisodesCharacterizing Chromatin at the Nuclear Lamina (Bas van Steensel)Single Cell Epigenomics in Neuronal Development (Tim Petros)The Role of Histone Dopaminylation and Serotinylation in Neuronal Plasticity (Ian Maze)ContactEpigenetics Podcast on MastodonEpigenetics Podcast on BlueskyDr. Stefan Dillinger on LinkedInActive Motif on LinkedInActive Motif on BlueskyEmail: [email protected]