近日,，美國喬治亞醫(yī)學(xué)院的科學(xué)家解碼了神經(jīng)元交流的記憶形成和重喚機制,。在實時識別記憶形成和回憶方面的突破性進展為客觀全面的記憶研究開辟了一條新的道路，同時也有助于開發(fā)更好的療法。這項研究結(jié)果發(fā)布在12月16日PLoS ONE上,。
在這項研究中,，科學(xué)家使用了新的技術(shù)和計算方法，并結(jié)合巴甫洛夫式訓(xùn)練,。
在大腦的記憶中樞,，研究人員使用128個電極檢測神經(jīng)元的活性，能夠同時記錄老鼠大腦中200到300個神經(jīng)元的交流,。另外,，還結(jié)合了巴甫洛夫式訓(xùn)練，即先給老鼠聽一個固定的音調(diào),，并在20秒后對腳進行輕微的電擊,。
研究中使用的算法將神經(jīng)元的活動轉(zhuǎn)化為一種可識別的動態(tài)模式，使得科學(xué)家能夠追蹤記憶的形式,，比如形成和回憶,。通過監(jiān)聽神經(jīng)元的活性，科學(xué)家能夠破譯神經(jīng)元實時的動態(tài)模式以及交流方式,。
雖然每次回憶的時候，蹤跡有輕微的改變,，這可能是老鼠的情緒和所處的環(huán)境變化導(dǎo)致的,，但是仍然可以認(rèn)為是一種特殊的記憶。
研究人員隨后進行了老鼠訓(xùn)練行為的記憶重喚,。他們發(fā)現(xiàn)蹤跡與記憶得分緊密相關(guān),。低得分的老鼠軌跡暗淡，軌跡越強行為表現(xiàn)越好,。
就如研究人員預(yù)料的,，當(dāng)老鼠在1小時候后返回原來的訓(xùn)練環(huán)境中時，它們就重復(fù)表現(xiàn)出呆滯行為,，在大腦中的記憶模式被喚醒后,。當(dāng)置于陌生的環(huán)境中時，老鼠會在聽到聲音后出現(xiàn)呆滯行為,。該研究一項最令人驚奇的發(fā)現(xiàn)是,，腳休克的蹤跡是單獨記憶的。
大腦最基本的認(rèn)知功能能夠在任何水平的學(xué)習(xí),，鞏固,，存儲，重喚過程中發(fā)生,。實時觀察記憶的形成經(jīng)有助于尋找記憶問題發(fā)生的準(zhǔn)確位點,，并進行更多的靶向研究和治療。（生物谷Bioon.com）
相關(guān)運用巴甫洛夫式訓(xùn)練的實驗：
Nature：微生物的主動應(yīng)對行為
Current Biology：果蠅實驗顯示群體環(huán)境更有利于記憶
Nature：多巴胺神經(jīng)元的復(fù)雜性
生物谷推薦原始出處：
PLoS ONE 4(12): e8256. doi:10.1371/journal.pone.0008256
Neural Population-Level Memory Traces in the Mouse Hippocampus
Guifen Chen, L. Phillip Wang, Joe Z. Tsien*
Brain and Behavior Discovery Institute and Department of Neurology, School of Medicine, Medical College of Georgia, Augusta, Georgia, United States of America
One of the fundamental goals in neurosciences is to elucidate the formation and retrieval of brain's associative memory traces in real-time. Here, we describe real-time neural ensemble transient dynamics in the mouse hippocampal CA1 region and demonstrate their relationships with behavioral performances during both learning and recall. We employed the classic trace fear conditioning paradigm involving a neutral tone followed by a mild foot-shock 20 seconds later. Our large-scale recording and decoding methods revealed that conditioned tone responses and tone-shock association patterns were not present in CA1 during the first pairing, but emerged quickly after multiple pairings. These encoding patterns showed increased immediate-replay, correlating tightly with increased immediate-freezing during learning. Moreover, during contextual recall, these patterns reappeared in tandem six-to-fourteen times per minute, again correlating tightly with behavioral recall. Upon traced tone recall, while various fear memories were retrieved, the shock traces exhibited a unique recall-peak around the 20-second trace interval, further signifying the memory of time for the expected shock. Therefore, our study has revealed various real-time associative memory traces during learning and recall in CA1, and demonstrates that real-time memory traces can be decoded on a moment-to-moment basis over any single trial.
