2026-09-01 オークリッジ国立研究所（ORNL）
＜関連情報＞
- https://www.ornl.gov/news/scientists-discover-learning-and-memory-formation-model-membranes
- https://advanced.onlinelibrary.wiley.com/doi/full/10.1002/aelm.202500759
- https://www.pnas.org/doi/10.1073/pnas.2510664122
- https://pubs.acs.org/langd5/article-abstract/41/5/2973/3744256/Neuronal-Plasma-Membranes-as-Supramolecular?redirectedFrom=fulltext
- https://medibio.tiisys.com/104357/
光応答性ロタキサンが光によって脂質二重層のニューロモルフィック挙動を切り替える Photoresponsive Rotaxanes Switch Lipid Bilayer Neuromorphic Behavior with Light
P.T. Podar, U.N.K. Conthagamage, J. Katsaras, V. García-López, C. P. Collier
Advanced Electronic Materials Published: 23 March 2026
DOI:https://doi.org/10.1002/aelm.202500759
ABSTRACT
A rotaxane consisting of a macrocycle ring with two azobenzene units mechanically interlocked onto a bolaamphiphilic axle was incorporated into droplet interface bilayers (DIBs). The azobenzene groups on the ring underwent quasi-reversible, photoisomerization-induced cycling between 1-E and 1–Z configurations when irradiated with 370 and 467 nm light, respectively, enabling programmable access to different history-dependent electrical behaviors from the same membrane. In the 1-E configuration, bilayers exhibited type-IIactive memristance that coincided with increasingly elevated ionic conduction, associated with progressively enhanced bilayer permeability during voltage cycling. In the 1-Z configuration, bilayers displayed type-I, passive memcapacitive behavior, reflecting tighter lipid packing and reduced ionic permeability. Photoswitching also yielded a nonvolatile, photoresponsive memcapacitor that could be modulated repetitively with negligible loss, likely via reversible changes in membrane thickness. Concurrent ohmic leakage currents across the membrane were less than 0.3%. These results agree with previous studies with increasing membrane permeability using photoswitchable rotaxanes and provide new insights into the coupling between volatile and nonvolatile memcapacitance during photoisomerization. More broadly, they demonstrate a new strategy for the manipulation of neuromorphic behaviors in soft materials using light, with implications for brain-inspired computation and sensing.
電気機械的に誘発される膜構造変化は学習と記憶を可能にする Electromechanically induced membrane restructuring enables learning and memory
Peter T. Podar, Dima Bolmatov, Teshani Kumarage, +7 , and John Katsaras
Proceedings of the National Academy of Sciences Published:November 4, 2025
DOI:https://doi.org/10.1073/pnas.2510664122
Abstract
Human neural networks of interconnected neurons have evolved to be remarkably efficient and are capable of learning and memory through the brain’s synaptic plasticity, including short-term plasticity (STP), and long-term potentiation (LTP) and depression (LTD). These activity-dependent mechanisms induce changes in synaptic efficiency over both transient and extended timescales. Understanding the molecular basis of learning and memory is central to deciphering brain function and advancing therapeutics for neurodegenerative diseases. Here, we report that lipid bilayers with embedded gramicidin A ion channels can structurally reorganize when interrogated using a neurologically inspired electrical stimulation protocol, adopting metastable structures with enhanced STP response and emergent LTP or LTD. Specifically, voltage-induced electrocompression is found to restructure membranes, driving them into nonequilibrium steady states with enhanced stability and increased ionic conductivity, leading to stronger and persistent membrane ion conductance. These results show how membrane restructuring and emergent complexity may regulate synaptic plasticity at the molecular level.
神経細胞の形質膜は生物学的記憶のための超分子集合体として機能する Neuronal Plasma Membranes as Supramolecular Assemblies for Biological Memory
C. Patrick Collier;Dima Bolmatov;Ralph Lydic;John Katsaras
Langmuir Published:January 18, 2025
DOI:https://doi.org/10.1021/acs.langmuir.4c03375
Abstract
Biological memory is the ability to develop, retain, and retrieve information over time. Currently, it is widely accepted that memories are stored in synapses (i.e., connections between brain cells throughout the brain) through a process known as synaptic plasticity, which leads to either long-term potentiation (LTP) or long-term depression (LTD). However, the strengthening (LTP) and weakening (LTD) of synapses involve post-translational modifications to neural networks requiring de novo gene expression, a lengthy and energetically expensive process. Recently, we observed that lipid bilayers in the absence of peptides/proteins are capable of LTP, not unlike what has been observed in mammals and birds. As such, this finding has prompted us to postulate that the lipid bilayer provides a good model for understanding the molecular basis of biological memory. In this article, we discuss the status, challenges, and opportunities of neuronal plasma membranes as structures for biological memory and learning, therapeutic targets for various brain disorders, and platforms for neural network developments.
