Protein synthesis-dependent memory and neuronal enhancement in Hermissenda are contingent on parameters of training and retention.
Protein synthesis-dependent memory and neuronal enhancement in Hermissenda are contingent on parameters of training and retention.
复制标题
Hermissenda 中蛋白质合成依赖性记忆和神经元增强取决于训练和保留的参数。
DOI：
10.1101/lm.4.6.462
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Matzel,LD
中科院分区：
文献类型：
--
作者：
Ramirez,RR;Gandhi,CC;Muzzio,IA;Matzel,LD
在连续配对的光和旋转之后，光单独激发Hermissenda的脚的条件性收缩，指示联想记忆。经过5分钟的保留间隔，这种条件反射是明显的两个或九个（但不是一个）条件试验，但持续90分钟后，只有九个试验。在体内孵育的动物中的蛋白质合成抑制剂茴香霉素（ANI; 1 μ M）没有影响的条件反应在5分钟的保留时间间隔，但显着衰减条件反应在90分钟的间隔，即使经过9次训练试验。去乙酰茴香霉素（DANI; 1 μ M;茴香霉素的一种非活性形式）对5分钟或90分钟的保留时间没有影响。在伴随程序中，各组孤立的神经系统暴露于可比较的光和旋转配对，并且B光感受器（被认为是存储关联记忆的部位）进行电生理学分析。B光感受器中神经元兴奋性的增加（通过对注入电流的去极化电压反应来索引）抑制了完整动物中条件反应的表达，即，两次训练试验产生了兴奋性的短期增加，在45分钟内消散，而九次试验产生了兴奋性的持续增加（至少90分钟）。在最后的实验中，分离的神经系统暴露于9个训练试验，ANI或DANI或者在训练之前和训练期间存在于洗浴介质中，或者在训练后5分钟引入。在ANI中训练后，观察到B光感受器的兴奋性短期（5- 45分钟）但不持久（90分钟）增加。ANI没有影响的短期或持续增加兴奋性，如果药物应用5分钟后，最后一次（第九次）的训练试验，和DANI没有影响训练诱导的兴奋性增加在任何保留间隔。这些结果表明，短期保留在Hermissenda是蛋白质合成独立的，但新的蛋白质合成过程中或训练后不久开始的事件是必要的，即使是90分钟的保留。此外，这些结果表明，在某些条件下，必须超过一个临界阈值的训练，以启动蛋白质合成依赖性保留。
Following contiguous pairings of light and rotation, light alone elicits a conditioned contraction of Hermissenda's foot, indicative of an associative memory. After a 5-min retention interval, this conditioned response was evident following two or nine (but not one) conditioning trials but persisted for 90 min only after nine trials. In vivo incubation of animals in the protein synthesis inhibitor anisomycin (ANI; 1 microM) did not affect the conditioned response at the 5-min retention interval but significantly attenuated conditioned responding at the 90-min interval even following nine training trials. Deacetylanisomycin (DANI; 1 microM; an inactive form of anisomycin) had no effect on either 5- or 90-min retention. In a companion procedure, groups of isolated nervous systems were exposed to comparable light and rotation pairings, and the B photoreceptors (considered a site of storage for the associative memory) underwent electrophysiological analysis. An increase in neuronal excitability (indexed by depolarizing voltage responses to injected current) in the B photoreceptors paralleled the expression of conditioned responding in intact animals, that is, two training trials produced a short-term increase in excitability that dissipated within 45 min, whereas nine trials produced a persistent (at least 90-min) increase in excitability. In a fmal experiment, isolated nervous systems were exposed to nine training trials, and ANI or DANI was either present in the bathing medium before and during training or was introduced 5 min after training. Following training in ANI, a short-term (5- to 45-min) but not persistent (90-min) increase in excitability in the B photoreceptors was observed. ANI had no effect on either the short-term or persistent increase in excitability if the drug was applied 5 min after the last (ninth) training trial, and DANI had no effect on training-induced increases in excitability at any retention intervals. These results suggest that short-term retention in Hermissenda is protein synthesis independent but that new protein synthesis initiated during or shortly after the training event is necessary for even 90-min retention. Moreover, these results indicate that under some conditions, a critical threshold of training must be exceeded to initiate protein synthesis-dependent retention.