Though it has been known for over half a century that interference with the normal activity of septohippocampal neurons can abolish hippocampal theta rhythmicity, a definitive answer to the question of its function has remained elusive. To clarify the role of septal circuits and theta in location-specific activity of place cells and spatial behavior, three drugs were delivered to the medial septum of rats: Tetracaine, a local anesthetic; muscimol, a GABA-A agonist; and gabazine, a GABA-A antagonist. All three drugs disrupted normal oscillatory activity in the hippocampus. However, tetracaine and muscimol both reduced spatial firing and interfered with the rat's ability to navigate to a hidden goal. After gabazine, location-specific firing was preserved in the absence of theta, but rats were unable to accurately locate the hidden goal. These results indicate that theta is unnecessary for location-specific firing of hippocampal cells, and that place cell activity cannot support accurate navigation when septal circuits are disrupted.

中文翻译：

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没有完整的隔膜回路，位置细胞放电不能支持导航。

尽管半个多世纪以来人们已经知道干扰海马神经元的正常活动可以消除海马 theta 节律性，但对其功能问题的明确答案仍然难以捉摸。为了阐明隔膜回路和θ在位置细胞的位置特异性活动和空间行为中的作用，将三种药物递送至大鼠的内侧隔膜：丁卡因，一种局部麻醉剂；muscimol，一种 GABA-A 激动剂；和 gabazine，一种 GABA-A 拮抗剂。所有三种药物都破坏了海马体的正常振荡活动。然而，丁卡因和 muscimol 都减少了空间激发并干扰了大鼠导航到隐藏目标的能力。在 gabazine 之后，在没有 theta 的情况下保留了特定位置的射击，但大鼠无法准确定位隐藏的目标。