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

人们一直认为，记忆的获得、保持和回忆是由神经元群的活动介导的，这些神经元群是通过学习和经验形成和重组的。在这项研究中，我们成像海马CA1区神经元电路活动的头部固定的小鼠在虚拟现实中进行空间行为，通过使用双光子脑深部成像的转基因小鼠表达基因编码的钙指标在大脑中。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的位置特异性活动。我们还观察到，不同虚拟位置场的神经元在海马CA1区局部回路中相互交织。

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.