Although the hypothalamus is classified into more than 10 compartments, it still contains uncharacterized areas. In this study, we identified a new triangular-shaped area between the paraventricular hypothalamic nucleus (PVN) and the fornix area in the mouse anterior hypothalamus, which is enriched in chondroitin sulfate proteoglycans (CSPGs). We designated this region as the perifornical area of the anterior hypothalamus (PeFAH) based on its anatomical location. As evidenced by Nissl staining, the PeFAH was distinguishable as an area of relatively low density. Immunohistochemical and DNA microarray analyses indicated that PeFAH contains sparsely distributed calretinin-positive neurons and densely clustered enkephalin-positive neurons. Furthermore, the PeFAH was shown to have bidirectional neural connections with the lateral septum. Indeed, we confirmed enkephalinergic projections from PeFAH neurons to the lateral septum, and inversely, calbindin-positive lateral septum neurons as afferents to the PeFAH. Finally, c-Fos expression analysis revealed that the activity of certain PeFAH neuronal populations tended to be increased by psychological stressors, but not that of enkephalinergic neurons. We proposed PeFAH as a new region in the AH.

中文翻译：

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涉及下丘脑回路的小鼠下丘脑的新定义区域：下丘脑前部的腹膜周围区域，PeFAH。

尽管下丘脑被划分为10多个隔室，但其仍包含未表征的区域。在这项研究中，我们在小鼠下丘脑前丘脑室旁下丘脑核（PVN）和穹ni区域之间发现了一个新的三角形区域，该区域富含硫酸软骨素蛋白聚糖（CSPGs）。根据其解剖位置，我们将该区域指定为下丘脑前部（PeFAH）的椎管周围区域。Nissl染色证明，PeFAH可以区分为相对低密度的区域。免疫组织化学和DNA芯片分析表明，PeFAH包含稀疏分布的钙网蛋白阳性神经元和密集簇集的脑啡肽阳性神经元。此外，显示出PeFAH与侧隔具有双向神经连接。的确，我们证实了从PeFAH神经元到外侧中隔的脑啡肽投射，相反，从CalFAdin阳性的外侧中隔神经元向PeFAH传入神经。最后，c-Fos表达分析表明，某些PeFAH神经元群体的活动倾向于由心理压力增加，而不是由脑啡肽能神经元增加。我们建议将PeFAH作为AH的新区域。