魏茨曼科學研究院(Weizmann Institue of Science)神經(jīng)生物所的科學家Ilan Lampl博士發(fā)現(xiàn)了一個具有說服力的證據(jù),，說明神經(jīng)細胞傳訊的可能真相，這項研究發(fā)表于近期的Neuron期刊,。
細胞在中樞神經(jīng)系統(tǒng)會傾向于與其它細胞溝通，乃是藉由電訊號在神經(jīng)元中傳遞訊息,，問題是：大腦要怎么轉(zhuǎn)譯這些信息,，才能讓我們感知及理解在我們面前的世界呢,？大部分的人認為這些電訊號會產(chǎn)生一些圖譜(patterns)，轉(zhuǎn)譯為不同的認知信息,，因此,，大腦可以辨識桌子或椅子，因為每種東西都會在神經(jīng)系統(tǒng)中產(chǎn)生不同序列的圖譜,，而大腦會對這些圖譜給予不同的批注,。重復出現(xiàn)的物體，其圖譜便會很精確在神經(jīng)系統(tǒng)的支配下出現(xiàn)一樣的圖譜,。
然而,，當Lampl及其研究團隊記錄并分析被麻醉的大鼠腦皮層(cortex)的活動時，他們發(fā)現(xiàn)產(chǎn)生圖譜的數(shù)目與形態(tài)并沒有差異,，因此,，他們推論先前看到的圖譜，可能不是由于神經(jīng)細胞電訊號所傳達而來的,，而僅是偶然發(fā)生的情況罷了,。這項研究結(jié)果看來似乎對于神經(jīng)訊息傳遞的爭議有明顯的貢獻，Lampl博士說：「自1980年代起,，許多神經(jīng)科學家都相信神經(jīng)電訊號傳訊理論,，但這份研究卻提供了強烈的證據(jù)，大腦似乎不是用這些圖譜來轉(zhuǎn)譯感知信息的,?！?/p>
(資料來源 : Bio.com)
Neuron, Vol 53, 413-425, 01 February 2007
Article
Stochastic Emergence of Repeating Cortical Motifs in Spontaneous Membrane Potential Fluctuations In Vivo
Alik Mokeichev,1,2 Michael Okun,1,3 Omri Barak,1 Yonatan Katz,1 Ohad Ben-Shahar,2 and Ilan Lampl1,
1 Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
2 Department of Computer Science and The Zlotowski Center for Neuroscience, Ben Gurion University of the Negev, Beer-Sheva 84105, Israel
3 Department of Computer Science, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
Corresponding author
Ilan Lampl
[email protected]
Summary
It was recently discovered that subthreshold membrane potential fluctuations of cortical neurons can precisely repeat during spontaneous activity, seconds to minutes apart, both in brain slices and in anesthetized animals. These repeats, also called cortical motifs, were suggested to reflect a replay of sequential neuronal firing patterns. We searched for motifs in spontaneous activity, recorded from the rat barrel cortex and from the cat striate cortex of anesthetized animals, and found numerous repeating patterns of high similarity and repetition rates. To test their significance, various statistics were compared between physiological data and three different types of stochastic surrogate data that preserve dynamical characteristics of the recorded data. We found no evidence for the existence of deterministically generated cortical motifs. Rather, the stochastic properties of cortical motifs suggest that they appear by chance, as a result of the constraints imposed by the coarse dynamics of subthreshold ongoing activity.
