6月 16, 2024

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私たちの脳の仕組みに関する画期的な仮説

私たちの脳の仕組みに関する画期的な仮説

新しい研究は、「細胞電気結合」と呼ばれる仮説を提案し、神経ネットワークの活動によって生成される脳電場が、ニューロンの細胞内成分の物理的構成に影響を与え、ネットワークの安定性と効率を向上させる可能性があると主張している。 MIT、ロンドン市立大学、ジョンズ・ホプキンス大学の科学者らによって行われたこの研究は、リズミカルな電気活動、つまり「脳波」がどのように神経ネットワーク内で調整し、分子レベルで電場に影響を与え、調整するかを示した以前の研究に基づいている。脳の機能を高め、柔軟な認知を促進します。

脳波は情報の伝達手段として機能します。 最近提案された「細胞電気結合」仮説は、これらの振動電場が脳ネットワークの効率と強度の向上に寄与していることを示唆しています。 彼らは、脳の分子フレームワークの物理的構成に影響を与えることによってこれを行います。

思考を含む多面的な機能を実行するために、脳はさまざまなレベルで働きます。 ターゲットや視覚化などの情報は、ニューラル ネットワーク間の同期された電気的活動を通じて取得されます。 同時に、各ニューロン内およびその周囲の多数のタンパク質およびその他の生化学物質が、これらのネットワークに参加するために必要なメカニズムを実行します。

MIT、ロンドン市立大学、ジョンズ・ホプキンス大学の研究者らによる新しい論文は、ネットワーク電場がニューロンの細胞内成分の物理的構成に影響を与え、ネットワークの安定性と効率を向上させると仮定しており、著者らはこの仮説を「細胞電気」と呼んでいる。 カップリング。」

アール K. ミラー

キャスト アール K. ピッカー学習記憶研究所で最近の研究について講演するミラー氏。 クレジット: MIT ピコワー研究所

アール・Kはこう言いました。 ミラー、ピコワー ミシガン大学ピコワー学習記憶研究所教授[{” attribute=””>MIT, who co-authored the paper in Progress in Neurobiology with Associate Professor Dimitris Pinotsis of MIT and City —University of London, and Professor Gene Fridman of Johns Hopkins.

“The brain adapts to a changing world,” Pinotsis said. “Its proteins and molecules change too. They can have electric charges and need to catch up with neurons that process, store, and transmit information using electric signals. Interacting with the neurons’ electric fields seems necessary.”

Thinking in fields

A major focus of Miller’s lab is studying how higher-level cognitive functions such as working memory can rapidly, flexibly, and yet reliably emerge from the activity of millions of individual neurons. Neurons are capable of dynamically forming circuits by creating and removing connections, called synapses, as well as strengthening or weakening those junctions. But, that merely forms a “roadmap” around which information could flow, Miller said.

The specific neural circuits that collectively represent one thought or another, Miller has found, are coordinated by rhythmic activity, more colloquially known as “brain waves” of different frequencies.

Fast “gamma” rhythms help transmit images from our vision (e.g. a muffin), while slower “beta” waves might carry our deeper thoughts about that image, (e.g. “too many calories”). Properly timed, bursts of these waves can carry predictions, enable writing in, holding onto, and reading out information in working memory, Miller’s lab has shown.

They break down when working memory does, too. The lab has reported evidence that the brain might distinctly manipulate rhythms in specific physical locations to further organize neurons for flexible cognition, a concept called “Spatial Computing.

Other recent work from the lab has shown that while the participation of individual neurons within networks may be fickle and unreliable, the information carried by the networks they are part of is stably represented by the overall electric fields generated by their collective activity.

 Cytoelectric coupling

In the new study, the authors combine this model of rhythmic electrical activity coordinating neural networks with other lines of evidence that electrical fields can influence neurons at the molecular level.

Researchers, for example, have studied ephaptic coupling, in which neurons influence each other’s electrical properties via the proximity of their membranes, rather than solely relying on electrochemical exchanges across synapses. This electrical cross-talk can affect neural functions including when and whether they spike to relay electrical signals to other neurons in a circuit.

Miller, Pinotsis, and Fridman also cite research showing other electrical influences on cells and their components including how neural development is guided by fields and that microtubules can be aligned by them.

If the brain carries information in electric fields and those electric fields are capable of configuring neurons and other elements in the brain that form a network, then the brain is likely to use this capability. The brain can use fields to ensure the network does what it is supposed to do, the authors suggest.

To put it (loosely) in couch potato terms, the success of a television network isn’t just its ability to transmit a clear signal to millions of homes. What’s also important is the details as fine as the way each viewer household arranges its TV, sound system, and living room furniture to maximize the experience. Both in this metaphor and in the brain, Miller said, the presence of the network motivates the individual participants to configure their own infrastructure to participate optimally.

“Cytoelectric Coupling connects information at the meso‐ and macroscopic level down to the microscopic level of proteins that are the molecular basis of memory,” the authors wrote in the paper.

The article lays out the logic inspiring Cytoelectic Coupling. “We’re offering a hypothesis that anybody can test,” Miller said.

Reference: “Cytoelectric coupling: Electric fields sculpt neural activity and “tune” the brain’s infrastructure” by Dimitris A. Pinotsis, Gene Fridman and Earl K. Miller, 18 May 2023, Progress in Neurobiology.
DOI: 10.1016/j.pneurobio.2023.102465

The study was funded by the United Kingdom Research and Innovation (UKRI), the U.S. Office of Naval Research, The JPB Foundation, and The Picower Institute for Learning and Memory.

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