大多數(shù)人曾有過“似曾相識(shí)”的經(jīng)歷,。美國(guó)研究人員已經(jīng)確定導(dǎo)致這一感覺發(fā)生的大腦區(qū)域,，并認(rèn)為這一發(fā)現(xiàn)有助于治療與記憶力相關(guān)的疾病,。
據(jù)路透社８日?qǐng)?bào)道,，麻省理工學(xué)院生物學(xué)和神經(jīng)科學(xué)教授利根川進(jìn)和同事在《科學(xué)》雜志上發(fā)表了這一研究結(jié)果,。
研究人員說,，大腦記憶中心有一部分神經(jīng)細(xì)胞被稱作海馬狀突起。當(dāng)人來到新地方,、有新經(jīng)歷時(shí),，這部分神經(jīng)細(xì)胞會(huì)就此“畫”出一份記憶“地圖”，然后把這些記憶藏起來,，以備后用,。
然而如果有兩次經(jīng)歷非常相似，它們的“地圖”會(huì)重合,，變得不清楚,。
利根川進(jìn)說，這一情況發(fā)生時(shí)，大腦就會(huì)出現(xiàn)似曾相識(shí)的感覺,。實(shí)際上,，這只是因?yàn)榇竽X對(duì)新信息，也就是情景記憶,，進(jìn)行分類時(shí)發(fā)生了功能故障,。
利根川進(jìn)說：“這種功能對(duì)像人類這樣的智慧生物而言非常重要。有了它,，你知道身邊發(fā)生了什么事,，并能在稍后回想起來。”
他還說,，大腦的這種功能隨著年齡增長(zhǎng)而逐漸衰退,，這在老年癡呆癥患者身上尤為明顯。根據(jù)他們的研究結(jié)果,，人們有希望開發(fā)出藥物改進(jìn)這一功能,。（生物谷援引新華網(wǎng)）
原始出處:
Published Online June 7, 2007
Science DOI: 10.1126/science.1140263
Research Articles
Submitted on January 23, 2007
Accepted on May 23, 2007
Dentate Gyrus NMDA Receptors Mediate Rapid Pattern Separation in the Hippocampal Network
Thomas J. McHugh 1, Matthew W. Jones 2, Jennifer J. Quinn 3, Nina Balthasar 4, Roberto Coppari 5, Joel K. Elmquist 5, Bradford B. Lowell 6, Michael S. Fanselow 7, Matthew A. Wilson 8, Susumu Tonegawa 1*
1 The Picower Institute for Learning and Memory, RIKEN-MIT Neuroscience Research Center, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
2 The Picower Institute for Learning and Memory, RIKEN-MIT Neuroscience Research Center, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Present address: Department of Physiology, University of Bristol, Bristol BS8 1TD, UK.
3 Department of Psychology, University of California-Los Angeles, Los Angeles, CA 90095, USA; Present address: Division of Molecular Psychiatry, Yale University, New Haven, CT 06508, USA.
4 Division of Endocrinology, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA; Present address: Department of Physiology, University of Bristol, Bristol BS8 1TD, UK.
5 Division of Endocrinology, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA; Present address: Center for Hypothalamic Research, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
6 Division of Endocrinology, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
7 Department of Psychology, University of California-Los Angeles, Los Angeles, CA 90095, USA.
8 The Picower Institute for Learning and Memory, RIKEN-MIT Neuroscience Research Center, Department of Biology and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
* To whom correspondence should be addressed.
Susumu Tonegawa , E-mail: [email protected]
Abstract
Forming distinct representations of multiple contexts, places and episodes is a crucial function of the hippocampus. The dentate gyrus subregion has been suggested to fulfill this role. We have tested this hypothesis by generating and analyzing a mouse strain that lacks the gene encoding the essential subunit of the N-methyl-D-aspartate (NMDA) receptor, NR1, specifically in dentate gyrus granule cells. The mutant mice performed normally in contextual fear conditioning, but were impaired in the ability to distinguish two similar contexts. A significant reduction in the context-specific modulation of firing rate was observed in the CA3 pyramidal cells when the mutant mice were transferred from one context to another. These results provide evidence that NMDA receptors in the granule cells of the dentate gyrus play a crucial role in the process of pattern separation.
