Structural synaptic modifications associated with hippocampal LTP and behavioral learning
Structural synaptic modifications associated with hippocampal LTP and behavioral learning
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DOI：
10.1093/cercor/10.10.952
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发表时间：
2000-10-01
期刊：
影响因子：
3.7
通讯作者：
Geinisman, Y
中科院分区：
文献类型：
--
作者：
Geinisman, Y
记忆神经生物学中的一个重要问题是学习和记忆的细胞机制是否包括新突触的形成或现有突触的重塑。为了阐明这个问题，许多研究检查了行为学习和海马长时增强（LTP）后突触数量和结构的变化，LTP被视为记忆的突触模型。本文对文献中报告的数据和本实验室获得的数据进行分析，以评估哪种结构修饰可能解释与学习和记忆相关的突触可塑性。已经证明，LTP 诱导会引发激活的轴突末端和新出现的树突棘之间额外突触的形成。同样，某些形式的学习已被证明可以增加突触的数量。尽管许多检查 LTP 或学习效果的超微结构研究未能发现突触总数的变化，但这种群体测量可能无法检测到由激活末端建立的一小部分突触的增加。 LTP 和学习也被证明可以诱导突触的重塑。该过程被提议涉及将某些突触亚型转变为更有效的亚型，包括将“沉默”突触转变为功能性突触。因此，学习和记忆的细胞机制很可能包括突触发生和突触重塑。
An important problem in the neurobiology of memory is whether cellular mechanisms of learning and memory include the formation of new synapses or the remodeling of existing ones. To elucidate this problem, numerous studies have examined alterations in the number and structure of synapses following behavioral learning and hippocampal lone-term potentiation (LTP), which is viewed as a synaptic model of memory The data reported in the literature and obtained in this laboratory are analyzed here to evaluate what kind of structural modification is likely to account for synaptic plasticity associated with learning and memory. It has been demonstrated that LTP induction elicits the formation of additional synapses between activated axon terminals and newly emerging dendritic spines. Similarly, some forms of learning have been shown to increase the number of synapses. Although many ultrastructural studies examining the effect of LTP or learning failed to find a change in total synapse number, this population measure might not detect an increase in a small proportion of synapses established by activated terminals. LTP and learning have also been shown to induce a remodeling of synapses. This process is proposed to involve the transformation of certain synaptic subtypes into more efficacious ones, including the conversion of 'silent' synapses into functional synapses. It appears, therefore, that cellular mechanisms of learning and memory are likely to include both synaptogenesis and synapse remodeling.