Cholecystokinin-expressing interneurons (CCKIs) are hypothesized to shape pyramidal cell-firing patterns and regulate network oscillations and related network state transitions. To directly probe their role in the CA1 region, we silenced their activity using optogenetic and chemogenetic tools in mice. Opto-tagged CCKIs revealed a heterogeneous population, and their optogenetic silencing triggered wide disinhibitory network changes affecting both pyramidal cells and other interneurons. CCKI silencing enhanced pyramidal cell burst firing and altered the temporal coding of place cells: theta phase precession was disrupted, whereas sequence reactivation was enhanced. Chemogenetic CCKI silencing did not alter the acquisition of spatial reference memories on the Morris water maze but enhanced the recall of contextual fear memories and enabled selective recall when similar environments were tested. This work suggests the key involvement of CCKIs in the control of place-cell temporal coding and the formation of contextual memories.

中文翻译：

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海马表达胆囊收缩素的中间神经元调节时间编码和情境学习


推测表达胆囊收缩素的中间神经元（CCKI）可以塑造锥体细胞放电模式并调节网络振荡和相关的网络状态转换。为了直接探究它们在 CA1 区域中的作用，我们使用小鼠中的光遗传学和化学遗传学工具来沉默它们的活性。光标记的 CCKI 揭示了一个异质群体，它们的光遗传学沉默引发了广泛的去抑制网络变化，影响锥体细胞和其他中间神经元。 CCKI 沉默增强了锥体细胞爆发放电并改变了位置细胞的时间编码：θ 相进动被破坏，而序列重新激活被增强。化学遗传学 CCKI 沉默不会改变莫里斯水迷宫上空间参考记忆的获取，但增强了情境恐惧记忆的回忆，并在测试类似环境时实现了选择性回忆。这项工作表明 CCKI 在位置细胞时间编码的控制和情境记忆的形成中发挥着关键作用。