Influence of the hippocampus on interneurons of the rat prefrontal cortex
Influence of the hippocampus on interneurons of the rat prefrontal cortex
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DOI：
10.1111/j.1460-9568.2004.03501.x
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发表时间：
2004-07
影响因子：
3.4
通讯作者：
P. Tierney;Eric Dégénétais;A. Thierry;J. Glowinski;Y. Gioanni
中科院分区：
文献类型：
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作者：
P. Tierney;Eric Dégénétais;A. Thierry;J. Glowinski;Y. Gioanni
海马体和前额叶皮层（PFC）是与学习和记忆过程有关的两个结构，通过直接的海马-前额叶通路连接起来。研究表明，PFC 锥体细胞接收来自海马体的单突触兴奋性输入，在这项研究中，我们试图确定海马体对麻醉大鼠 PFC 中间神经元的影响。将细胞外记录与神经生物素或生物素化右旋糖胺的细胞旁注射相结合，以在形态上区分中间神经元和锥体细胞。在所有情况下，标记中间神经元的动作电位持续时间较短（0.70 ms）。海马 CA1/下下区的单脉冲刺激在记录的 PFC 前边缘和内侧眼眶区域中 70% 的中间神经元中引起兴奋反应。与锥体细胞产生的一到两个动作电位相反，一组重要的中间神经元响应海马刺激而激发出一阵动作电位。这些兴奋性反应的很大一部分可能是单突触的，因为它们的潜伏期与海马-前额叶通路的传导时间一致。此外，当同时记录锥体细胞和中间神经元并且两者都对刺激做出反应时，中间神经元始终先于锥体细胞放电。总之，海马对 PFC 中间神经元产生直接兴奋性影响，因此能够前馈抑制锥体细胞。海马输出通过这种抑制过程在空间和时间上集中，因此可以促进 PFC 神经元的特定子集与海马活动的同步。
The hippocampus and prefrontal cortex (PFC), two structures implicated in learning and memory processes, are linked by a direct hippocampo‐prefrontal pathway. It has been shown that PFC pyramidal cells receive monosynaptic excitatory inputs from the hippocampus and, in this study, we sought to determine the influence of the hippocampus on PFC interneurons in anesthetized rats. Extracellular recordings were coupled to juxtacellular injections of neurobiotin or biotinylated dextran amine to morphologically differentiate interneurons from pyramidal cells. In all cases, the action potentials of labeled interneurons were of shorter duration ( 0.70 ms). Single pulse stimulation of the hippocampal CA1/subiculum region induced an excitatory response in 70% of recorded interneurons in the prelimbic and medial‐orbital areas of the PFC. In contrast to the one to two action potentials generated by pyramidal cells, an important group of interneurons fired a burst of action potentials in response to hippocampal stimulation. A large proportion of these excitatory responses was probably monosynaptic as their latency is consistent with the conduction time of the hippocampo‐prefrontal pathway. In addition, when both a pyramidal cell and an interneuron were simultaneously recorded and both responded to stimulation, the interneuron consistently fired before the pyramidal cell. In conclusion, the hippocampus exerts a direct excitatory influence on PFC interneurons and is thus capable of feedforward inhibition of pyramidal cells. Hippocampal output is spatially and temporally focalized via this inhibitory process and consequently could facilitate the synchronization of a specific subset of PFC neurons with hippocampal activity.