Jones Matthew W, Wilson Matthew A
Department of Brain and Cognitive Sciences, The Picower Institute for Learning and Memory, RIKEN-MIT Neuroscience Research Center, Massachusetts Institute of Technology, Cambridge, 02139, USA.
Hippocampus. 2005;15(7):867-73. doi: 10.1002/hipo.20119.
Theta phase-locking and phase precession are two related phenomena reflecting coordination of hippocampal place cell firing with the local, ongoing theta rhythm. The mechanisms and functions of both the phenomena remain unclear, though the robust correlation between firing phase and location of the animal has lead to the suggestion that this phase relationship constitutes a temporal code for spatial information. Recent work has described theta phase-locking in the rat medial prefrontal cortex (mPFC), a structure with direct anatomical and functional links to the hippocampus. Here, we describe an initial characterization of phase precession in the mPFC relative to the CA1 theta rhythm. mPFC phase precession was most robust during behavioral epochs known to be associated with enhanced theta-frequency coordination of CA1 and mPFC activities. Precession was coherent across the mPFC population, with multiple neurons precessing in parallel as a function of location of the animal. The existence of phase precession beyond the hippocampus implies a more global role for this phenomenon during theta rhythm-mediated coordination of neural activity.
θ 相位锁定和相位进动是两种相关现象，反映了海马体位置细胞放电与局部持续的 θ 节律之间的协调性。尽管放电相位与动物位置之间存在强烈的相关性，这表明这种相位关系构成了空间信息的时间编码，但这两种现象的机制和功能仍不清楚。最近的研究描述了大鼠内侧前额叶皮层（mPFC）中的 θ 相位锁定，该结构与海马体有直接的解剖学和功能联系。在这里，我们描述了相对于 CA1 θ 节律，mPFC 中相位进动的初步特征。mPFC 相位进动在已知与 CA1 和 mPFC 活动增强的 θ 频率协调性相关的行为时期最为明显。进动在 mPFC 群体中是连贯的，多个神经元根据动物的位置平行进动。海马体之外相位进动的存在意味着这种现象在 θ 节律介导的神经活动协调中具有更广泛的作用。
