DeCoteau William E, Thorn Catherine, Gibson Daniel J, Courtemanche Richard, Mitra Partha, Kubota Yasuo, Graybiel Ann M
Department of Psychology, St. Lawrence University, Canton, NY 13617, USA.
Proc Natl Acad Sci U S A. 2007 Mar 27;104(13):5644-9. doi: 10.1073/pnas.0700818104. Epub 2007 Mar 19.
The striatum and hippocampus are conventionally viewed as complementary learning and memory systems, with the hippocampus specialized for fact-based episodic memory and the striatum for procedural learning and memory. Here we directly tested whether these two systems exhibit independent or coordinated activity patterns during procedural learning. We trained rats on a conditional T-maze task requiring navigational and cue-based associative learning. We recorded local field potential (LFP) activity with tetrodes chronically implanted in the caudoputamen and the CA1 field of the dorsal hippocampus during 6-25 days of training. We show that simultaneously recorded striatal and hippocampal theta rhythms are modulated differently as the rats learned to perform the T-maze task but nevertheless become highly coherent during the choice period of the maze runs in rats that successfully learned the task. Moreover, in the rats that acquired the task, the phase of the striatal-hippocampal theta coherence was modified toward a consistent antiphase relationship, and these changes occurred in proportion to the levels of learning achieved. We suggest that rhythmic oscillations, including theta-band activity, could influence not only neural processing in cortico-basal ganglia circuits but also dynamic interactions between basal ganglia-based and hippocampus-based forebrain circuits during the acquisition and performance of learned behaviors. Experience-dependent changes in coordination of oscillatory activity across brain structures thus may parallel the well known plasticity of spike activity that occurs as a function of experience.
纹状体和海马体传统上被视为互补的学习和记忆系统，海马体专门负责基于事实的情景记忆，而纹状体则负责程序性学习和记忆。在此，我们直接测试了这两个系统在程序性学习过程中是否表现出独立或协同的活动模式。我们训练大鼠完成一项条件性T迷宫任务，该任务需要导航和基于线索的联想学习。在6至25天的训练过程中，我们用长期植入尾壳核和背侧海马体CA1区的四极管记录局部场电位（LFP）活动。我们发现，随着大鼠学会执行T迷宫任务，同时记录的纹状体和海马体θ节律受到不同程度的调制，但在成功学会任务的大鼠进行迷宫奔跑的选择期，它们的节律变得高度相干。此外，在学会任务的大鼠中，纹状体 - 海马体θ相干的相位朝着一致的反相位关系改变，并且这些变化与学习达到的水平成比例。我们认为，包括θ频段活动在内的节律性振荡不仅可能影响皮质 - 基底神经节回路中的神经处理，还可能影响在习得行为的获取和执行过程中基于基底神经节的前脑回路与基于海马体的前脑回路之间的动态相互作用。因此，大脑结构间振荡活动协调的经验依赖性变化可能与众所周知的随经验而发生的动作电位活动可塑性并行。
