Guth Tim A, Brandt Armin, Reinacher Peter C, Schulze-Bonhage Andreas, Jacobs Joshua, Kunz Lukas
Department of Epileptology, University Hospital Bonn, Bonn, Germany.
Epilepsy Center, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany.
Nat Commun. 2025 Aug 11;16(1):7402. doi: 10.1038/s41467-025-62553-9.
Memory processes may rely on complex interactions between single-neuron activity and local field potentials. To better understand such spike-field relationships in humans, we examined human theta-phase locking-neuronal firing at similar theta phases over time-using single-neuron recordings in epilepsy patients performing a spatial memory task. Applying frequency-adaptive theta-phase estimation in a broad 1-10 Hz frequency range, we found that theta-phase locking was widespread in the human medial temporal lobe during memory encoding and retrieval. Time-resolved spectral parameterization and cycle-by-cycle analysis demonstrated stronger theta-phase locking during steep aperiodic slopes and prominent theta oscillations. Phase-locking strength was similar across successful and unsuccessful memory trials, with most neurons spiking at similar theta phases during encoding and retrieval. Some neurons shifted their preferred phase, supporting theories that encoding and retrieval are separated within the theta cycle. These results show how local field potential properties and memory states influence human theta-phase locking.
记忆过程可能依赖于单神经元活动与局部场电位之间的复杂相互作用。为了更好地理解人类中的此类峰-场关系，我们在癫痫患者执行空间记忆任务时使用单神经元记录，研究了随时间推移在相似θ相位下的人类θ相位锁定-神经元放电情况。在1-10赫兹的宽频率范围内应用频率自适应θ相位估计，我们发现，在记忆编码和检索过程中，θ相位锁定在人类内侧颞叶中广泛存在。时间分辨谱参数化和逐周期分析表明，在陡峭的非周期斜率和显著的θ振荡期间，θ相位锁定更强。在成功和未成功的记忆试验中，锁相强度相似，大多数神经元在编码和检索过程中在相似的θ相位处放电。一些神经元改变了它们的偏好相位，这支持了编码和检索在θ周期内是分开的理论。这些结果表明了局部场电位特性和记忆状态如何影响人类的θ相位锁定。
