新研究表明特定區(qū)域的腦中,，新生神經(jīng)元在早期發(fā)育過(guò)程中的經(jīng)歷，會(huì)影響它們?cè)诔赡昴X中的存活和活性,。這些新生神經(jīng)元存儲(chǔ)這些經(jīng)歷的方式,，可以用以解釋它們?nèi)绾斡绊懗赡陚€(gè)體學(xué)習(xí)和記憶的過(guò)程。美國(guó)Salk研究所的Fred Gage領(lǐng)導(dǎo)研究小組完成了此項(xiàng)研究,。
研究者發(fā)現(xiàn)：經(jīng)歷可以加強(qiáng)腦中齒狀回（*）區(qū)域的新生神經(jīng)元的存活,，而且相同經(jīng)歷的出現(xiàn)會(huì)激活更多這類(lèi)的神經(jīng)元。這種功能上的轉(zhuǎn)變可能是長(zhǎng)期記憶（**）的內(nèi)在機(jī)制,。研究文章發(fā)表在3月21日的《The Journal of Neuroscience》雜志上,。
“研究結(jié)果識(shí)別出了一個(gè)特定的時(shí)期，在這個(gè)時(shí)期經(jīng)歷可以增強(qiáng)海馬（***）中新生神經(jīng)元的存活,，”普林斯頓大學(xué)的Elizabeth Gould介紹說(shuō),，他沒(méi)有參與此項(xiàng)研究。海馬包括齒狀回這一區(qū)域,。
Gage介紹說(shuō)：“今后的研究將會(huì)致力于在記憶相關(guān)的行為過(guò)程中,，經(jīng)歷是如何影響神經(jīng)元的活性的，以及這對(duì)于其他的腦區(qū)域有何影響,。”感興趣的讀者可以參看英文原文,。
部分英文原文：
The Journal of Neuroscience, March 21, 2007, 27(12):3252-3259; doi:10.1523/JNEUROSCI.4941-06.2007
Experience-Specific Functional Modification of the Dentate Gyrus through Adult Neurogenesis: A Critical Period during an Immature Stage
Ayumu Tashiro, Hiroshi Makino, and Fred H. Gage
Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California 92037
Correspondence should be addressed to Fred H. Gage, 10010 North Torrey Pines Road, La Jolla, CA 92037. Email: [email protected]
Neural circuits in the dentate gyrus are continuously modified by adult neurogenesis, whose level is affected by the animal's experience. However, it is not known whether this experience-dependent anatomical modification alters the functional properties of the dentate gyrus. Here, using the expression of immediate early gene products, c-fos and Zif268, as indicators of recently activated neurons, we show that previous exposure to an enriched environment increases the total number of new neurons and the number of new neurons responding to reexposure to the same environment. The increase in the density of activated new neurons occurred specifically in response to exposure to the same environment but not to a different experience. Furthermore, we found that these experience-specific modifications are affected exclusively by previous exposure around the second week after neuronal birth but not later than 3 weeks. Thus, the animal's experience within a critical period during an immature stage of new neurons determines the survival and population response of the new neurons and may affect later neural representation of the experience in the dentate gyrus. This experience-specific functional modification through adult neurogenesis could be a mechanism by which new neurons exert a long-term influence on the function of the dentate gyrus related to learning and memory.
Key words: enriched environment; c-fos; zif268; immediate early gene; dentate gyrus; hippocampus; memory; neurogenesis
