近日,，美國喬治亞醫(yī)學院的科學家解碼了神經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,。這項研究結果發(fā)布在12月16日PLoS ONE上,。
在這項研究中，科學家使用了新的技術和計算方法,，并結合巴甫洛夫式訓練,。
在大腦的記憶中樞，研究人員使用128個電極檢測神經元的活性,，能夠同時記錄老鼠大腦中200到300個神經元的交流,。另外，還結合了巴甫洛夫式訓練,，即先給老鼠聽一個固定的音調,，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元的活動轉化為一種可識別的動態(tài)模式,，使得科學家能夠追蹤記憶的形式,，比如形成和回憶,。通過監(jiān)聽神經元的活性，科學家能夠破譯神經元實時的動態(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)境變化導致的,，但是仍然可以認為是一種特殊的記憶,。
研究人員隨后進行了老鼠訓練行為的記憶重喚。他們發(fā)現(xiàn)蹤跡與記憶得分緊密相關,。低得分的老鼠軌跡暗淡,，軌跡越強行為表現(xiàn)越好。
就如研究人員預料的,，當老鼠在1小時候后返回原來的訓練環(huán)境中時,，它們就重復表現(xiàn)出呆滯行為，在大腦中的記憶模式被喚醒后,。當置于陌生的環(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,。
大腦最基本的認知功能能夠在任何水平的學習，鞏固,，存儲,，重喚過程中發(fā)生。實時觀察記憶的形成經有助于尋找記憶問題發(fā)生的準確位點,，并進行更多的靶向研究和治療,。（生物谷Bioon.com）
相關運用巴甫洛夫式訓練的實驗：
Nature：微生物的主動應對行為
Current Biology：果蠅實驗顯示群體環(huán)境更有利于記憶
Nature：多巴胺神經元的復雜性
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.
