Role of delayed nonsynaptic neuronal plasticity in long-term associative memory
Role of delayed nonsynaptic neuronal plasticity in long-term associative memory
复制标题
DOI：
10.1016/j.cub.2006.05.049
复制
发表时间：
2006-07-11
期刊：
影响因子：
9.2
通讯作者：
Benjamin, Paul R.
中科院分区：
文献类型：
--
作者：
Kemenes, Ildiko;Straub, Volko A.;Benjamin, Paul R.
工作背景：现在已经确定，学习后会发生持续的非突触神经元可塑性，并且像突触可塑性一样，它可以是长期记忆的基质。然而，仍然不清楚的是，非突触可塑性如何影响记忆所依赖的神经网络特性的改变。因此，了解非突触可塑性如何转化为修改的网络和行为输出是当前学习和记忆研究的一个重要目标。通过使用行为单次经典条件反射结合电生理分析和钙成像，我们已经探索了细胞机制，在远离突触区域的神经元索马中诱导的非突触电变化被转化为突触和回路水平效应。我们表明，在蜗牛椎实螺（Lymnaea stagnalis）中进行单次食物奖励条件反射后，已识别的摄食网络外部调节神经元在训练后16至24小时内变得持续去极化。这是延迟相对于早期记忆的形成，但伴随着长期记忆的建立和持续时间。持续的非突触变化是外在的，并保持独立的突触内发生的网络直接负责产生喂养的影响。人工膜电位操纵和钙成像实验提出了一种新的机制，即外部神经元的小去极化招募了作为学习行为基础的回路的命令样内在神经元。我们发现，非突触可塑性在一个外部调制神经元编码的信息，使长期联想记忆的表达，我们描述了如何将这些信息转化为修改后的网络和行为输出。
Background: It is now well established that persistent nonsynaptic neuronal plasticity occurs after learning and, like synaptic plasticity, it can be the substrate for long-term memory. What still remains unclear, though, is how nonsynaptic plasticity contributes to the altered neural network properties on which memory depends. Understanding how nonsynaptic plasticity is translated into modified network and behavioral output therefore represents an important objective of current learning and memory research.Results: By using behavioral single-trial classical conditioning together with electrophysiological analysis and calcium imaging, we have explored the cellular mechanisms by which experience-induced nonsynaptic electrical changes in a neuronal soma remote from the synaptic region are translated into synaptic and circuit level effects. We show that after single-trial food-reward conditioning in the snail Lymnaea stagnalis, identified modulatory neurons that are extrinsic to the feeding network become persistently depolarized between 16 and 24 hr after training. This is delayed with respect to early memory formation but concomitant with the establishment and duration of long-term memory. The persistent nonsynaptic change is extrinsic to and maintained independently of synaptic effects occurring within the network directly responsible for the generation of feeding. Artificial membrane potential manipulation and calcium-imaging experiments suggest a novel mechanism whereby the small depolarization of an extrinsic neuron recruits command-like intrinsic neurons of the circuit underlying the learned behavior.Conclusions: We show that nonsynaptic plasticity in an extrinsic modulatory neuron encodes information that enables the expression of long-term associative memory, and we describe how this information can be translated into modified network and behavioral output.