Temporal dynamics of learning-promoted synaptic diversity in CA1 pyramidal neurons.
Temporal dynamics of learning-promoted synaptic diversity in CA1 pyramidal neurons.
复制标题
CA1 锥体神经元学习促进突触多样性的时间动态。
DOI：
10.1096/fj.201801893rrr
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Mitsushima D.
中科院分区：
文献类型：
--
作者：
Sakimoto Y;Kida H;Mitsushima D.
尽管情境学习需要 Cornu ammonis 1 (CA1) 神经元的兴奋性和抑制性 (E/I) 突触具有可塑性，但我们对整个神经元群体的时间动态知之甚少。使用抑制性回避任务，我们分析了学习引起的 E/I 突触可塑性的动态变化。训练在1分钟内增强GABAA受体介导的突触，在10分钟达到峰值，并持续60多分钟。 GABAA 受体 β3 亚基的细胞内环 (Ser408−409) 也在训练后 1 分钟内被磷酸化。由于 α-氨基-3-羟基-5-甲基-4-异恶唑-丙酸酯受体介导的突触增强，CA1 锥体神经元在 5 分钟内表现出广泛的 E/I 突触电流多样性。此外，基底树突突触前谷氨酸释放概率也在 5 分钟内增加。为了进一步量化多样化的 E/I 突触电流，我们计算了单个神经元的自熵（位）。神经元显示出参数的个体水平，该参数在训练后 1 分钟内迅速增加，并维持超过 60 分钟。这些结果表明，学习引起的突触可塑性在编码后立即变得至关重要，而不是在学习的检索阶段。了解时间动态以及突触多样性的量化对于确定认知障碍中学习促进可塑性的失败点是必要的。-Sakimoto, Y., Kida, H., Mitsushima, D. CA1 锥体神经元中学习促进突触多样性的时间动态。
Although contextual learning requires plasticity at both excitatory and inhibitory (E/I) synapses in cornu ammonis 1 (CA1) neurons, the temporal dynamics across the neuronal population are poorly understood. Using an inhibitory avoidance task, we analyzed the dynamic changes in learning-induced E/I synaptic plasticity. The training strengthened GABAA receptor–mediated synapses within 1 min, peaked at 10 min, and lasted for over 60 min. The intracellular loop (Ser408−409) of GABAA receptor β3 subunit was also phosphorylated within 1 min of training. As the results of strengthening of α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate receptor–mediated synapses, CA1 pyramidal neurons exhibited broad diversity of E/I synaptic currents within 5 min. Moreover, presynaptic glutamate release probability at basal dendrites also increased within 5 min. To further quantify the diversified E/I synaptic currents, we calculated self-entropy (bit) for individual neurons. The neurons showed individual levels of the parameter, which rapidly increased within 1 min of training and maintained for over 60 min. These results suggest that learning-induced synaptic plasticity is critical immediately following encoding rather than during the retrieval phase of the learning. Understanding the temporal dynamics along with the quantification of synaptic diversity would be necessary to identify a failure point for learning-promoted plasticity in cognitive disorders.—Sakimoto, Y., Kida, H., Mitsushima, D. Temporal dynamics of learning-promoted synaptic diversity in CA1 pyramidal neurons.