Center for Neural Science, New York University, New York, New York 10003.
Center for Neural Science, New York University, New York, New York 10003
J Neurosci. 2018 Aug 15;38(33):7351-7363. doi: 10.1523/JNEUROSCI.0378-18.2018. Epub 2018 Jun 29.
Inputs from the ventral hippocampus (vHPC) to the prefrontal cortex (PFC) play a key role in working memory and emotional control. However, little is known about how excitatory inputs from the vHPC engage different populations of neurons in the PFC. Here we use optogenetics and whole-cell recordings to study the cell-type specificity of synaptic connections in acute slices from the mouse PFC. We first show that vHPC inputs target pyramidal neurons whose cell bodies are located in layer (L)2/3 and L5 of infralimbic (IL) PFC, but only in L5 of prelimbic (PL) PFC, and not L6 of either IL or PL. We then compare connections onto different classes of projection neurons located in these layers and subregions of PFC. We establish vHPC inputs similarly contact corticocortical (CC) and cortico-amygdala neurons in L2/3 of IL, but preferentially target CC neurons over cortico-pontine neurons in L5 of both IL and PL. Of all these neurons, we determine that vHPC inputs are most effective at driving action potential (AP) firing of CC neurons in L5 of IL. We also show this connection exhibits frequency-dependent facilitation, with repetitive activity enhancing AP firing of IL L5 CC neurons, even in the presence of feedforward inhibition. Our findings reveal how vHPC inputs engage defined populations of projection neurons in the PFC, allowing preferentially activation of the intratelencephalic network. We examined the impact of connections from the ventral hippocampus (vHPC) onto different projection neurons in the mouse prefrontal cortex (PFC). We found vHPC inputs were strongest at corticocortical neurons in layer 5 of infralimbic PFC, where they robustly evoked action potential firing, including during repetitive activity with intact feedforward inhibition.
腹侧海马体（vHPC）到前额叶皮层（PFC）的输入在工作记忆和情绪控制中起着关键作用。然而，对于 vHPC 的兴奋性输入如何使 PFC 中的不同神经元群体参与，我们知之甚少。在这里，我们使用光遗传学和全细胞记录来研究来自小鼠 PFC 的急性切片中突触连接的细胞类型特异性。我们首先表明，vHPC 输入靶向位于边缘下（IL）PFC 的 L2/3 和 L5 层以及前扣带回（PL）PFC 的 L5 层的锥体神经元，但仅在 PL 的 L5 层，而不是 IL 的 L6 层。然后，我们比较了位于这些层和 PFC 亚区的不同类型的投射神经元的连接。我们确定 vHPC 输入相似地接触位于 IL 的 L2/3 中的皮质皮质（CC）和皮质杏仁核神经元，但优先靶向 CC 神经元而不是 IL 和 PL 的 L5 中的皮质桥神经元。在所有这些神经元中，我们确定 vHPC 输入在驱动 IL 的 L5 的 CC 神经元的动作电位（AP）发射方面最有效。我们还表明，这种连接表现出频率依赖性易化，重复活动增强了 IL L5 CC 神经元的 AP 发射，即使在存在前馈抑制的情况下也是如此。我们的研究结果揭示了 vHPC 输入如何与 PFC 中的特定投射神经元群体结合，从而优先激活脑内网络。我们检查了来自腹侧海马体（vHPC）的连接对小鼠前额叶皮层（PFC）中不同投射神经元的影响。我们发现 vHPC 输入在边缘下 PFC 的 L5 层的皮质皮质神经元中最强，在那里它们强烈地诱发动作电位发射，包括在具有完整前馈抑制的重复活动期间。
