Wang Ziqun, Wang Tao, Yang Fan, Liu Feng, Wang Wei
National Laboratory of Solid State Microstructures, Department of Physics, Collaborative Innovation Center of Advanced Microstructures, and Institute for Brain Sciences, Nanjing University, Nanjing 210093, P. R. China.
iScience. 2023 Mar 14;26(4):106351. doi: 10.1016/j.isci.2023.106351. eCollection 2023 Apr 21.
Both grid-like firing fields and theta oscillation are hallmarks of grid cells in the mammalian brain. While bump attractor dynamics have generally been recognized as the substrate for grid firing fields, how theta oscillation arises and interacts with persistent activity in a cortical circuit remains obscure. Here, we report that the theta oscillation intrinsically emerges in a continuous attractor network composed of principal neurons and interneurons. Periodic bump attractors and the theta rhythm stably coexist in both cell types due to the division of labor among interneurons via structured synaptic connectivity between principal cells and interneurons. The slow dynamics of NMDAR-mediated synaptic currents support the persistency of bump attractors and restrict the oscillation frequency in the theta band. The spikes of neurons within bump attractors are phase locked to a proxy of local field potential. The current work provides a network-level mechanism that orchestrates the bump attractor dynamics and theta rhythmicity.
网格状放电场和θ振荡都是哺乳动物大脑中网格细胞的标志。虽然 bump 吸引子动力学通常被认为是网格放电场的基础，但θ振荡如何产生以及如何与皮层回路中的持续活动相互作用仍不清楚。在这里，我们报告θ振荡在由主神经元和中间神经元组成的连续吸引子网络中内在地出现。由于中间神经元通过主细胞和中间神经元之间的结构化突触连接进行分工，周期性 bump 吸引子和θ节律在两种细胞类型中稳定共存。NMDAR 介导的突触电流的缓慢动力学支持 bump 吸引子的持续性，并限制θ频段的振荡频率。bump 吸引子内神经元的尖峰与局部场电位的代理锁相。目前的工作提供了一种网络层面的机制，协调 bump 吸引子动力学和θ节律性。
