Computation and Neural Systems and Division of Biology, California Institute of Technology, Pasadena, California 91125, USA.
Nature. 2010 Apr 8;464(7290):903-7. doi: 10.1038/nature08860. Epub 2010 Mar 24.
Learning from novel experiences is a major task of the central nervous system. In mammals, the medial temporal lobe is crucial for this rapid form of learning. The modification of synapses and neuronal circuits through plasticity is thought to underlie memory formation. The induction of synaptic plasticity is favoured by coordinated action-potential timing across populations of neurons. Such coordinated activity of neural populations can give rise to oscillations of different frequencies, recorded in local field potentials. Brain oscillations in the theta frequency range (3-8 Hz) are often associated with the favourable induction of synaptic plasticity as well as behavioural memory. Here we report the activity of single neurons recorded together with the local field potential in humans engaged in a learning task. We show that successful memory formation in humans is predicted by a tight coordination of spike timing with the local theta oscillation. More stereotyped spiking predicts better memory, as indicated by higher retrieval confidence reported by subjects. These findings provide a link between the known modulation of theta oscillations by many memory-modulating behaviours and circuit mechanisms of plasticity.
从新的经验中学习是中枢神经系统的主要任务。在哺乳动物中，内侧颞叶对于这种快速学习形式至关重要。通过可塑性改变突触和神经元回路被认为是记忆形成的基础。突触可塑性的诱导有利于神经元群体的协调动作电位定时。这种神经群体的协调活动可以产生不同频率的振荡，在局部场电位中记录下来。脑振荡在 theta 频率范围内（3-8 Hz）通常与有利的突触可塑性诱导以及行为记忆有关。在这里，我们报告了人类在学习任务中记录的单个神经元的活动以及局部场电位。我们表明，与本地 theta 振荡的紧密协调的尖峰定时可以预测人类成功的记忆形成。更刻板的尖峰预测更好的记忆，这表明受试者报告的检索信心更高。这些发现为许多记忆调节行为对 theta 振荡的已知调制以及可塑性的电路机制之间提供了联系。
