New York University Neuroscience Institute, New York, NY, USA.
New York University Neuroscience Institute, New York, NY, USA; Center for Neural Science, New York University, New York, NY 10016, USA.
Curr Biol. 2023 Sep 11;33(17):3648-3659.e4. doi: 10.1016/j.cub.2023.07.039. Epub 2023 Aug 11.
Hippocampal sharp-wave ripples (SPW-Rs) are critical for memory consolidation and retrieval. The neuronal content of spiking during SPW-Rs is believed to be under the influence of neocortical inputs via the entorhinal cortex (EC). Optogenetic silencing of the medial EC (mEC) reduced the incidence of SPW-Rs with minor impacts on their magnitude or duration, similar to local CA1 silencing. The effect of mEC silencing on CA1 firing and field potentials was comparable to the effect of transient cortex-wide DOWN states of non-REM (NREM) sleep, implying that decreased SPW-R incidence in both cases is due to tonic disfacilitation of hippocampal circuits. The neuronal composition of CA1 pyramidal neurons during SPW-Rs was altered by mEC silencing but was restored immediately after silencing. We suggest that the mEC provides both tonic and transient influences on hippocampal network states by timing the occurrence of SPW-Rs and altering their neuronal content.
海马体锐波涟漪 (SPW-Rs) 对记忆的巩固和提取至关重要。在 SPW-Rs 期间，神经元的放电内容被认为受到来自内嗅皮层 (EC) 的新皮层输入的影响。光遗传沉默内侧 EC(mEC) 会降低 SPW-R 的发生率，对其幅度或持续时间的影响较小，与 CA1 沉默相似。mEC 沉默对 CA1 放电和场电位的影响与非快速眼动 (NREM) 睡眠期间短暂的全皮层去极化状态的影响相当，这意味着在这两种情况下，SPW-R 发生率的降低是由于海马回路的紧张性去抑制。mEC 沉默改变了 SPW-R 期间 CA1 锥体神经元的神经元组成，但在沉默后立即恢复。我们认为，mEC 通过定时发生 SPW-R 并改变其神经元内容，对海马体网络状态提供紧张性和瞬时影响。
