华东师范大学王智如等研究人员合作发现，联想学习引发的突触增强作用于与提示记忆获取相关的两个主要海马CA1输入。相关论文于2024年11月27日在线发表在《神经科学通报》杂志上。

在一次基于奖励的追踪条件反射学习中，研究人员测试了背侧CA1海马（dCA1）区域学习引发的突触可塑性。通过局部场电位记录结合选择性光遗传抑制，研究人员首次发现，在条件化过程中，dCA1区域对条件刺激（CS）的突触反应增强，这种增强作用发生在指向辐射层（Rad）的Schaffer侧支和指向分子层（LMol）的特定输入处。

在这些dCA1输入处，通过局部阻断NMDA受体并在条件化过程中进行全细胞记录，研究人员进一步证明了CS响应型兴奋性突触的突触增强。在Rad和LMol区域，通过多点记录发现突触增强的诱导时间进程大致相似；但与条件化行为反应相比，突触增强的出现较晚，饱和较早。

这些实验表明，基于提示的记忆相关dCA1突触可塑性，是在Schaffer侧支和特定角通路的共同作用下诱导的。

附：英文原文

Title: Associative Learning-Induced Synaptic Potentiation at the Two Major Hippocampal CA1 Inputs for Cued Memory Acquisition

Author: Wang, Bing-Ying, Wang, Bo, Cao, Bo, Gu, Ling-Ling, Chen, Jiayu, He, Hua, Zhao, Zheng, Chen, Fujun, Wang, Zhiru

Issue&Volume: 2024-11-27

Abstract: Learning-associated functional plasticity at hippocampal synapses remains largely unexplored. Here, in a single session of reward-based trace conditioning, we examine learning-induced synaptic plasticity in the dorsal CA1 hippocampus (dCA1). Local field-potential recording combined with selective optogenetic inhibition first revealed an increase of dCA1 synaptic responses to the conditioned stimulus (CS) induced during conditioning at both Schaffer collaterals to the stratum radiatum (Rad) and temporoammonic input to the lacunosum moleculare (LMol). At these dCA1 inputs, synaptic potentiation of CS-responding excitatory synapses was further demonstrated by locally blocking NMDA receptors during conditioning and whole-cell recording sensory-evoked synaptic responses in dCA1 neurons from naive animals. An overall similar time course of the induction of synaptic potentiation was found in the Rad and LMol by multiple-site recording; this emerged later and saturated earlier than conditioned behavioral responses. Our experiments demonstrate a cued memory-associated dCA1 synaptic plasticity induced at both Schaffer collaterals and temporoammonic pathways.

DOI: 10.1007/s12264-024-01327-7

Source: https://link.springer.com/article/10.1007/s12264-024-01327-7