The dorsal and ventral regions of the rat longitudinal hippocampal axis are functionally distinct. That is, each region is associated with different behavioral tasks and disease susceptibilities due to underlying anatomical, and physiological differences. These differences are especially pronounced in area CA1, where significant differences in morphology, synaptic physiology, intrinsic excitability, and gene expression have been reported between CA1 pyramidal neurons from the dorsal (DHC) and ventral hippocampus (VHC). However, despite a significant amount of recent attention, a cogent picture of the intrinsic electrophysiological profile of DHC and VHC neurons has remained elusive, due, in part, to experiments performed on rats at different developmental time points. Moreover, the resulting intrinsic electrophysiological profiles are sufficiently different as to warrant a thorough investigation of the spatial and temporal changes in the intrinsic excitability of CA1 pyramidal neurons across developmental time. Accordingly, in this study, I have characterized the intrinsic electrophysiological properties of CA1 pyramidal neurons from acute hippocampal slices prepared from the DHC and VHC throughout an approximately 3-week developmental period (P14-P37). DHC and VHC neurons exhibited distinct intra-region changes (DHC or VHC) and inter-region differences (DHC versus VHC) in their intrinsic electrophysiological properties, which yielded two developmental timelines: (a) a common developmental timeline describing changes observed in both DHC and VHC neurons, and (b) a differential developmental timeline highlighting unique features observed in DHC neurons. Specifically, DHC neurons exhibited significant inter-region differences in RMP, input resistance, threshold, and spike frequency adaptation relative to VHC neurons, as well as an intra-region change in the rebound slope (a proxy for Ih ). These observations both integrate and reconcile previous work performed with rats at different developmental stages and suggest a distinct developmental trajectory for DHC neurons that might shed light on the normal physiological functions and disease susceptibility of the DHC.

中文翻译：

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来自大鼠背侧和腹侧海马的 CA1 锥体神经元的内在电生理特性的差异发育细化。

大鼠纵向海马轴的背侧和腹侧区域在功能上是不同的。也就是说，由于潜在的解剖学和生理学差异，每个区域都与不同的行为任务和疾病易感性相关。这些差异在 CA1 区域尤为明显，据报道，来自背侧 (DHC) 和腹侧海马 (VHC) 的 CA1 锥体神经元在形态学、突触生理学、内在兴奋性和基因表达方面存在显着差异。然而，尽管最近引起了大量关注，但 DHC 和 VHC 神经元的内在电生理学特征的令人信服的图景仍然难以捉摸，部分原因是在不同发育时间点对大鼠进行的实验。而且，由此产生的内在电生理特征完全不同，以保证对 CA1 锥体神经元在整个发育时间内的内在兴奋性的空间和时间变化进行彻底调查。因此，在这项研究中，我表征了从 DHC 和 VHC 制备的急性海马切片中 CA1 锥体神经元在大约 3 周的发育期 (P14-P37) 中的内在电生理特性。DHC 和 VHC 神经元在其内在电生理特性方面表现出明显的区域内变化（DHC 或 VHC）和区域间差异（DHC 与 VHC），这产生了两个发育时间线：（a）一个共同的发育时间线，描述了在两个 DHC 中观察到的变化和 VHC 神经元，(b) 不同的发育时间线，突出了在 DHC 神经元中观察到的独特特征。具体而言，DHC 神经元相对于 VHC 神经元在 RMP、输入电阻、阈值和尖峰频率适应方面表现出显着的区域间差异，以及区域内反弹斜率的变化（Ih 的代表）。这些观察结果整合并协调了先前在不同发育阶段对大鼠进行的工作，并表明 DHC 神经元的独特发育轨迹可能揭示 DHC 的正常生理功能和疾病易感性。以及反弹斜率的区域内变化（Ih 的代理）。这些观察结果整合并协调了先前在不同发育阶段对大鼠进行的工作，并表明 DHC 神经元的独特发育轨迹可能揭示 DHC 的正常生理功能和疾病易感性。以及反弹斜率的区域内变化（Ih 的代理）。这些观察结果整合并协调了先前在不同发育阶段对大鼠进行的工作，并表明 DHC 神经元的独特发育轨迹可能揭示 DHC 的正常生理功能和疾病易感性。