生物谷報(bào)道： 成年腦中穩(wěn)定形成的新生腦細(xì)胞，在腦中可能遠(yuǎn)不止是扮演替補(bǔ)角色,，一項(xiàng)新的研究表明,。這些新生腦細(xì)胞可能具有讓成年腦獲得拓寬的學(xué)習(xí)本領(lǐng)，而這與已存在的成熟的腦中電路并不沖突,。Hongjun Song和同事于2007年5月24日《Neuron》雜志上發(fā)表的研究性文章,，詳細(xì)地描述了這一驚人的發(fā)現(xiàn)。
在實(shí)驗(yàn)過程中,，研究者運(yùn)用熒光蛋白選擇性地標(biāo)記海馬區(qū)的新生腦細(xì)胞,，而這個(gè)區(qū)域正是成年鼠腦中學(xué)習(xí)和記憶的中心。他們的結(jié)論是“成年腦中的神經(jīng)形成,，并不只是替代損失的神經(jīng)元，而很有可能讓神經(jīng)系統(tǒng)保持不斷更新,，從而在之后的生命過程中,，不斷保持可塑性。”
原始出處：
Neuron, Vol 54, 559-566, 24 May 2007
Article
A Critical Period for Enhanced Synaptic Plasticity in Newly Generated Neurons of the Adult Brain
Shaoyu Ge,1,2,3 Chih-hao Yang,1,2,4 Kuei-sen Hsu,4 Guo-li Ming,1,2,3 and Hongjun Song1,2,3,
1 Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
2 Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
3 The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
4 Department of Pharmacology, College of Medicine, National Cheng Kung University, No. 1, University Road, Tainan City 701, Taiwan
Corresponding author
Hongjun Song
[email protected]
Active adult neurogenesis occurs in discrete brain regions of all mammals and is widely regarded as a neuronal replacement mechanism. Whether adult-born neurons make unique contributions to brain functions is largely unknown. Here we systematically characterized synaptic plasticity of retrovirally labeled adult-born dentate granule cells at different stages during their neuronal maturation. We identified a critical period between 1 and 1.5 months of the cell age when adult-born neurons exhibit enhanced long-term potentiation with increased potentiation amplitude and decreased induction threshold. Furthermore, such enhanced plasticity in adult-born neurons depends on developmentally regulated synaptic expression of NR2B-containing NMDA receptors. Our study demonstrates that adult-born neurons exhibit the same classic critical period plasticity as neurons in the developing nervous system. The transient nature of such enhanced plasticity may provide a fundamental mechanism allowing adult-born neurons within the critical period to serve as major mediators of experience-induced plasticity while maintaining stability of the mature circuitry.
