Human hippocampal responses to network intracranial stimulation vary with theta phase.
Human hippocampal responses to network intracranial stimulation vary with theta phase.
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DOI：
10.7554/elife.78395
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发表时间：
2022-12-01
期刊：
影响因子：
7.7
通讯作者：
Voss JL
中科院分区：
文献类型：
--
作者：
Lurie SM;Kragel JE;Schuele SU;Voss JL
海马依赖性记忆被认为是由不同的连接状态支持的，海马的强输入有利于编码，弱输入有利于检索。先前对啮齿动物的研究表明，海马体的θ振荡协调了这些状态之间的转换，相反的相位角预测了最小和最大的输入。我们研究了这种相位依赖性是否存在于人类使用网络靶向颅内刺激。颅内局部场电位记录从个人癫痫进行医学必要的立体定向脑电图记录。在每名受试者中，双相双极直接电刺激被输送到侧颞部位，并证明与海马的连接。侧颞刺激诱发的同侧海马电位具有明显的早期和晚期成分。使用诱发成分振幅来测量功能连接，我们评估了海马theta相位是否预测相对高与低的连接。我们观察到增加的连续相位-振幅关系选择性的早期和晚期组件的响应引起的侧颞刺激。这些诱发成分振幅的最大差异发生在海马θ节律的180度分离上;也就是说，当在θ峰与谷处提供刺激时，观察到成分振幅的最大差异。在对照位置，没有发现海马体的θ相位依赖模式。这些发现表明，海马对输入的接受性随θ相位而变化，表明θ相位反映了人类海马网络的连接状态。这些发现证实了一个假定的机制，神经振荡调节人类海马功能。
Hippocampal-dependent memory is thought to be supported by distinct connectivity states, with strong input to the hippocampus benefitting encoding and weak input benefitting retrieval. Previous research in rodents suggests that the hippocampal theta oscillation orchestrates the transition between these states, with opposite phase angles predicting minimal versus maximal input. We investigated whether this phase dependence exists in humans using network-targeted intracranial stimulation. Intracranial local field potentials were recorded from individuals with epilepsy undergoing medically necessary stereotactic electroencephalographic recording. In each subject, biphasic bipolar direct electrical stimulation was delivered to lateral temporal sites with demonstrated connectivity to hippocampus. Lateral temporal stimulation evoked ipsilateral hippocampal potentials with distinct early and late components. Using evoked component amplitude to measure functional connectivity, we assessed whether the phase of hippocampal theta predicted relatively high versus low connectivity. We observed an increase in the continuous phase–amplitude relationship selective to the early and late components of the response evoked by lateral temporal stimulation. The maximal difference in these evoked component amplitudes occurred across 180 degrees of separation in the hippocampal theta rhythm; that is, the greatest difference in component amplitude was observed when stimulation was delivered at theta peak versus trough. The pattern of theta-phase dependence observed for hippocampus was not identified for control locations. These findings demonstrate that hippocampal receptivity to input varies with theta phase, suggesting that theta phase reflects connectivity states of human hippocampal networks. These findings confirm a putative mechanism by which neural oscillations modulate human hippocampal function.