Our Article Published in Nature Communications (Nature Portfolio)

We are excited to share that our article, “Astrocytic Ankyrin-2 Enables Memory Persistence in the Mouse Hippocampus”, has been published in Nature Communications and is now available online.

The Stars That Hold Our Memories

Why do some memories last for weeks, months, or even years, while others quickly fade away? Astrocytes may hold the key.

Memory persistence is a fundamental feature of memory, yet the cellular mechanisms that support the long-term stability of memory traces remain incompletely understood. While memory research has traditionally focused on neurons, increasing evidence suggests that astrocytes also play active roles in learning and memory.

In this study, we discovered Ankyrin-2 (Ank2), an autism risk gene, acts in astrocytes as a key regulator of memory persistence. Using astrocyte-specific Ank2 knockout mice, we found that loss of Ank2 impaired remote memory while leaving recent memory intact. These findings suggest that astrocytic Ank2 is not required for memory acquisition itself, but is critical for maintaining memories over time. We further showed that astrocytic Ank2 supports long-term potentiation (LTP), promotes structural interactions between astrocytes and memory-encoding engram neurons, and mediates BDNF-dependent astrocyte morphogenesis through TrkB.T1-IP3R2 signaling.

To test whether astrocytic BDNF signaling is sufficient to enhance memory persistence, we developed Opto-T1, an optogenetic tool that selectively activates astrocytic TrkB.T1 signaling. Remarkably, activation of this pathway enhanced remote memory and promoted the maintenance of synaptic plasticity.

Together, our findings reveal a previously unrecognized role of astrocytes in sustaining long-term memories and identify astrocytic Ank2 as a critical molecular component underlying memory persistence.

Graphical summary of our findings (from the article). Astrocytic Ankyrin-2 enables BDNF-dependent astrocyte morphogenesis and astrocyte-engram interactions, supporting long-term memory persistence.

This work was made possible through close collaboration among researchers at the Institute for Basic Science (IBS) and the Korea Brain Research Institute (KBRI). We are especially grateful to Drs. C. Justin Lee, Bong-Kiun Kaang, and Sangkyu Lee and their teams at IBS, as well as Drs. Kea Joo Lee and Gyu Hyun Kim at KBRI, for their invaluable contributions to this study. We also thank all members of the collaborating laboratories for their expertise, dedication, and support throughout this work. We look forward to continuing this line of research and further uncovering the cellular and molecular mechanisms that support memory and brain function !

Congratulations to our Hayoung Kim and also Drs Jiwoon Lim, Jooyoung Kim, and all the authors !!

Kim, H., Lim, J., Kim, J., Özkan, E., Kim, G. H., Park, H., Park, M. G., Joo, B., Lee, S., Lee, K. J., Kaang, B.-K., Lee, C. J., & Koh, W. Astrocytic Ankyrin-2 Enables Memory Persistence in the Mouse Hippocampus. Nature Communications (2026).