In cortical microcircuits, it is generally assumed that fast-spiking parvalbumin interneurons mediate dense and nonselective inhibition. Some reports indicate sparse and structured inhibitory connectivity, but the computational relevance and the underlying spatial organization remain unresolved. In the rat superficial presubiculum, we find that inhibition by fast-spiking interneurons is organized in the form of a dominant super-reciprocal microcircuit motif where multiple pyramidal cells recurrently inhibit each other via a single interneuron. Multineuron recordings and subsequent 3D reconstructions and analysis further show that this nonrandom connectivity arises from an asymmetric, polarized morphology of fast-spiking interneuron axons, which individually cover different directions in the same volume. Network simulations assuming topographically organized input demonstrate that such polarized inhibition can improve head direction tuning of pyramidal cells in comparison to a “blanket of inhibition.” We propose that structured inhibition based on asymmetrical axons is an overarching spatial connectivity principle for tailored computation across brain regions.

在皮质微电路中，通常假设快速尖峰小清蛋白中间神经元介导密集和非选择性抑制。一些报告表明稀疏和结构化的抑制连接，但计算相关性和潜在的空间组织仍未解决。在大鼠浅表骨下，我们发现快速尖峰中间神经元的抑制以占主导地位的超互易微电路基序的形式组织，其中多个锥体细胞通过单个中间神经元反复相互抑制。多神经元记录和随后的 3D 重建和分析进一步表明，这种非随机连接源于快速尖峰中间神经元轴突的不对称极化形态，它们分别覆盖同一体积中的不同方向。假设按地形组织输入的网络模拟表明，与“抑制毯”相比，这种极化抑制可以改善锥体细胞的头部方向调整。我们提出基于不对称轴突的结构化抑制是跨大脑区域定制计算的首要空间连接原则。