Sharp waves and ripples (SPW-Rs) are endogenous transient patterns of hippocampus local network activity implicated in several functions including memory consolidation, and they are diversified between the dorsal and the ventral hippocampus. Ion channels in the neuronal membrane play important roles in cell and local network function. In this study, using transverse slices and field potential recordings from the CA1 field of rat hippocampus we show that GIRK and KCNQ2/3 potassium channels play a higher role in modulating SPW-Rs in the dorsal hippocampus, while I_h and other KCNQ (presumably KCNQ5) channels, contribute to shaping SPW-R activity more in the ventral than in dorsal hippocampus. Specifically, blockade of I_h channels by ZD 7288 reduced the rate of occurrence of SPW-Rs and increased the generation of SPW-Rs in the form of clusters in both hippocampal segments, while enhanced the amplitude of SPW-Rs only in the ventral hippocampus. Most effects of ZD 7288 appeared to be independent of NMDA receptors' activity. However, the effects of blockade of NMDA receptors depended on the functional state of I_h channels in both hippocampal segments. Blockade of GIRK channels by Tertiapin-Q increased the rate of occurrence of SPW-Rs only in the dorsal hippocampus and the probability of clusters in both segments of the hippocampus. Blockade of KCNQ2/3 channels by XE 991 increased the rate of occurrence of SPW-Rs and the probability of clusters in the dorsal hippocampus, and only reduced the clustered generation of SPW-Rs in the ventral hippocampus. The blocker of KCNQ1/2 channels, that also enhances KCNQ5 channels, UCL 2077, increased the probability of clusters and the power of the ripple oscillation in the ventral hippocampus only. These results suggest that GIRK, KCNQ and I_h channels represent a key mechanism for modulation of SPW-R activity which act differently in the dorsal and ventral hippocampus, fundamentally supporting functional diversification along the dorsal-ventral axis of the hippocampus.

尖波和涟漪 (SPW-Rs) 是海马局部网络活动的内源性瞬态模式，涉及包括记忆巩固在内的多种功能，它们在背侧和腹侧海马之间多样化。神经元膜中的离子通道在细胞和局部网络功能中起着重要作用。在这项研究中，使用来自大鼠海马 CA1 场的横向切片和场电位记录，我们表明 GIRK 和 KCNQ2/3 钾通道在调节背侧海马的 SPW-Rs 中发挥着更高的作用，而 I _h和其他 KCNQ（大概KCNQ5) 通道更有助于塑造腹侧海马体中的 SPW-R 活性，而不是背侧海马体。具体来说，对 I _{h 的}封锁ZD 7288 的通道降低了 SPW-Rs 的发生率，并增加了两个海马段中以簇形式出现的 SPW-Rs，同时仅在腹侧海马中增强了 SPW-Rs 的振幅。ZD 7288 的大多数作用似乎与 NMDA 受体的活性无关。然而，阻断 NMDA 受体的效果取决于 I _h的功能状态两个海马段的通道。Tertiapin-Q 对 GIRK 通道的阻断仅在背侧海马体中增加了 SPW-Rs 的发生率，并增加了海马体两个节段中出现簇的概率。XE 991 对 KCNQ2/3 通道的阻断增加了 SPW-Rs 的发生率和背侧海马中成簇的概率，仅减少了腹侧海马中 SPW-Rs 的成簇生成。KCNQ1/2 通道的阻滞剂，也增强了 KCNQ5 通道，UCL 2077，仅增加了腹侧海马体中簇的概率和波纹振荡的功率。这些结果表明 GIRK、KCNQ 和 I _h 通道代表调节 SPW-R 活动的关键机制，其在背侧和腹侧海马中的作用不同，从根本上支持沿海马背腹轴的功能多样化。