生物谷報(bào)道：美國約翰·霍普金斯大學(xué)醫(yī)學(xué)院華裔科學(xué)家Hongjun Song領(lǐng)導(dǎo)的研究小組發(fā)現(xiàn),，成年大鼠新生神經(jīng)元具有與幼鼠相近的可塑性。相關(guān)論文發(fā)表在5月24日的《神經(jīng)元》（Neuron）雜志上。
過去的行為研究表明,，成年大鼠新產(chǎn)生的神經(jīng)元大約需要1到3周的時(shí)間才能融入現(xiàn)存的神經(jīng)網(wǎng)絡(luò)，但是此次研究結(jié)果顯示，神經(jīng)元的成熟期實(shí)際上可能長達(dá)4到6周。
Song等人檢測了成年大鼠海馬區(qū)新產(chǎn)生的齒狀回神經(jīng)元的電生理學(xué)特征，結(jié)果他們吃驚地發(fā)現(xiàn),，成年大鼠新生神經(jīng)元可塑性的變化模式與新生小鼠非常相似,。
該項(xiàng)研究表明，新生神經(jīng)元比成熟神經(jīng)元在形成記憶方面的作用更大,，這印證了之前成年大鼠利用新生神經(jīng)元完成空間記憶任務(wù)的研究結(jié)果,。
下一步科學(xué)家們將著手研究新生神經(jīng)元的特殊性質(zhì)，以及他們?cè)诖竽X中的特殊地位,。如果科學(xué)家們能夠發(fā)現(xiàn)年輕細(xì)胞的分子機(jī)制,，將向利用干細(xì)胞修復(fù)大腦損傷邁出重要的一步。
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]
Summary
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.
