Dept. Psychology, University of Otago, Dunedin, New Zealand.
Dept. Anatomy, University of Otago, Dunedin, New Zealand.
Neurosci Res. 2022 Sep;182:65-75. doi: 10.1016/j.neures.2022.06.006. Epub 2022 Jun 30.
Action stopping depends on at least two (fast, slow) frontal circuits depending on the urgency of execution of the 'go' response. Human EEG suggests a third (even slower, limbic) circuit that activates frontal areas at frequencies typical of 'hippocampal theta'. Here we test in male rats whether stop-go conflict engages the hippocampus and so may send theta-modulated information via the frontal cortex to the subthalamic nucleus. We recorded from multi-electrode arrays in the hippocampus, orbitofrontal cortex, and subthalamus in 5 male Long Evans rats performing a stop signal task and, as in previous human experiments, assessed stop-signal specific power for effects of goal conflict. Conflict increased 11-12 Hz theta power modestly in all three structures but with the largest increase in power being at 5 Hz in the frontal cortex but not the hippocampus. There was increased conflict-related coherence in all circuits in the range 5-8 Hz and particularly at 5-6 Hz. Increased coherence coupled with an increase in conflict-induced low frequency power in the frontal cortex may reflect communication with the hippocampus. The data are consistent with a third limbic circuit that can generate stopping when go responses are particularly slow (as, e.g., in a go/no go task). [199 words; 200 max].
动作停止依赖于至少两个（快速、慢速）额叶回路，这取决于“执行”反应的紧迫性。人类脑电图提示存在第三个（甚至更慢的、边缘的）回路，它以“海马 theta”典型的频率激活额叶区域。在这里，我们在雄性大鼠中测试了停止-去冲突是否涉及海马体，因此可能通过额叶皮层将 theta 调制信息发送到丘脑底核。我们在 5 只雄性 Long Evans 大鼠中记录了多电极阵列在海马体、眶额皮层和丘脑底核中的活动，这些大鼠在执行停止信号任务时，我们评估了与目标冲突相关的停止信号特异性功率。与以前的人类实验一样，冲突在所有三个结构中适度增加了 11-12 Hz 的 theta 功率，但在前额叶皮层中增加了 5 Hz 的功率，而在海马体中则没有。所有回路在 5-8 Hz 范围内的冲突相关相干性增加，特别是在 5-6 Hz 范围内。前额叶皮层中与冲突相关的相干性增加伴随着低频功率的增加，这可能反映了与海马体的交流。这些数据与第三个边缘回路一致，当去反应特别慢时（例如，在 Go/No Go 任务中），该回路可以产生停止。[199 个单词；200 个单词以内]
