Neuroscience Research Institute, Gachon University of Medicine and Science, Incheon, Republic of Korea.
Hippocampus. 2011 Jul;21(7):744-52. doi: 10.1002/hipo.20792. Epub 2010 May 7.
The relationship among brain electrophysiological activity, motor activity, and cognition has been a matter of great interest. For example, it has been discussed whether hippocampal theta rhythm reflects motor activity or cognitive activity, whereas it is widely accepted that the P300 event-related potential (ERP) reflects cognitive processes such as updating working memory. Here, we investigated the interrelationships among motor activity, hippocampal theta rhythm, and hippocampal P300 ERP using electrophysiological and behavioral data recorded from rats performing an auditory discrimination task (i.e., the auditory oddball paradigm) in a chamber with and without a running-wheel. We found that the hippocampal theta rhythm generated during locomotion codes information about self-motion, and event-related increases in hippocampal theta rhythm observed when rats performed the auditory discrimination cognitive task reflect a change in motor behavior after learning the cognitive task. Interestingly, the hippocampal P300 ERP occurred coincidently with increases in the power and frequency of hippocampal theta rhythm. In addition, we found that changes in theta rhythm observed during spontaneous wheel running without performing a cognitive task as well as when performing the cognitive task are associated with changes in delta- and gamma-band EEG activities. These major findings are discussed with respect to current hypotheses regarding P300 ERP and theta-, delta-, and gamma-band EEG activities in brain functions.
大脑电生理活动、运动活动和认知之间的关系一直是人们关注的焦点。例如，有人讨论过海马θ节律是否反映运动活动或认知活动，而广泛接受的观点是 P300 事件相关电位（ERP）反映了更新工作记忆等认知过程。在这里，我们使用在带有和不带有跑步轮的室中进行听觉辨别任务（即听觉Oddball 范式）的大鼠记录的电生理和行为数据，研究了运动活动、海马θ节律和海马 P300 ERP 之间的相互关系。我们发现，在运动过程中产生的海马θ节律编码了关于自身运动的信息，而当大鼠执行听觉辨别认知任务时观察到的与认知任务相关的海马θ节律增加反映了在学习认知任务后运动行为的变化。有趣的是，海马 P300 ERP 与海马θ节律的功率和频率增加同时发生。此外，我们发现，在没有执行认知任务的情况下进行自发轮跑时以及在执行认知任务时观察到的θ节律变化与δ和γ波段 EEG 活动的变化有关。这些主要发现与关于大脑功能中的 P300 ERP 和θ、δ和γ波段 EEG 活动的当前假说有关。
