學(xué)習(xí)和記憶形成被認為與腦回路的結(jié)構(gòu)變化相關(guān),。這種關(guān)聯(lián)的實驗證明一直難以找到，但現(xiàn)在兩個小組利用雙光子成像發(fā)現(xiàn),，突觸網(wǎng)絡(luò)重塑與穩(wěn)定的記憶存儲密切相關(guān),。在訓(xùn)練小鼠努力接觸某一目標(biāo)（即所謂的“reaching task”）的實驗中，Xu等人發(fā)現(xiàn)皮層神經(jīng)元幾小時內(nèi)有一個結(jié)構(gòu)反應(yīng)——新樹狀突脊的產(chǎn)生,。不同突脊以及由此產(chǎn)生的假定突觸集編碼截然不同的,、通過學(xué)習(xí)獲得的運動技能。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 462, 915-919 (17 December 2009) | doi:10.1038/nature08389
Rapid formation and selective stabilization of synapses for enduring motor memories
Tonghui Xu1,3, Xinzhu Yu1,3, Andrew J. Perlik1, Willie F. Tobin1, Jonathan A. Zweig1, Kelly Tennant2, Theresa Jones2 & Yi Zuo1
1 Department of Molecular, Cell and Developmental Biology, University of California Santa Cruz, Santa Cruz, California 95064, USA
2 Institute for Neuroscience, Department of Psychology, University of Texas at Austin, Austin, Texas 78712, USA
3 These authors contributed equally to this work.
Correspondence to: Yi Zuo1 Correspondence and requests for materials should be addressed to Y.Z.
Novel motor skills are learned through repetitive practice and, once acquired, persist long after training stops1, 2. Earlier studies have shown that such learning induces an increase in the efficacy of synapses in the primary motor cortex, the persistence of which is associated with retention of the task3, 4, 5. However, how motor learning affects neuronal circuitry at the level of individual synapses and how long-lasting memory is structurally encoded in the intact brain remain unknown. Here we show that synaptic connections in the living mouse brain rapidly respond to motor-skill learning and permanently rewire. Training in a forelimb reaching task leads to rapid (within an hour) formation of postsynaptic dendritic spines on the output pyramidal neurons in the contralateral motor cortex. Although selective elimination of spines that existed before training gradually returns the overall spine density back to the original level, the new spines induced during learning are preferentially stabilized during subsequent training and endure long after training stops. Furthermore, we show that different motor skills are encoded by different sets of synapses. Practice of novel, but not previously learned, tasks further promotes dendritic spine formation in adulthood. Our findings reveal that rapid, but long-lasting, synaptic reorganization is closely associated with motor learning. The data also suggest that stabilized neuronal connections are the foundation of durable motor memory.
