In vivo two-photon imaging of learning-induced hippocampal neuronal circuit plasticity

人们一直认为，记忆的获得、保持和回忆是通过学习和经验形成和重组的神经元组的活动来调节的。在这项研究中，我们使用双光子脑深部成像技术对在脑中表达遗传编码的钙指示物的转基因小鼠进行了双光子脑深部成像，从而成像了头部固定小鼠在虚拟现实中执行空间行为的海马区CA1神经元回路活动。我们从图像中计算提取了数百个神经元的活动时间序列，并证实了CA1锥体神经元的一个亚群表现出虚拟位置特定的活动。我们还观察到，具有不同虚拟位置场的神经元在解剖上相互混合在海马CA1局部回路中。

It has been thought that acquisition, retension and recall of memories are mediated by activity of groups of neurons that are formed and reorganized by learning and experience. In this study, we imaged hippocampal CA1 neuronal circuit activity in head-fixed mice performing spatial behavior in virtual reality by using two-photon deep brain imaging of transgenic mice expressing genetically-encoded calcium indicators in the brain. We computationally extracted activity time-series of hundreds of neurons from images and confirmed that a subpopulation of CA1 pyramidal neurons exhibited virtual place-specific activity. We also observed that neurons with different virtual place fields were anatomically intermingled each other in hippocampal CA1 local circuits.