The interplay between excitation and inhibition determines the fidelity of cortical representations. The receptive fields of excitatory neurons are often finely tuned to encoded features, but the principles governing the tuning of inhibitory neurons remain elusive. In this study, we recorded population of neurons in the mouse postsubiculum (PoSub), where the majority of excitatory neurons are head-direction (HD) cells. We show that the tuning of fast-spiking (FS) cells, the largest class of cortical inhibitory neurons, was broad and frequently radially symmetrical. By decomposing tuning curves using the Fourier transform, we identified an equivalence in tuning between PoSub-FS and PoSub-HD cell populations. Furthermore, recordings, optogenetic manipulations of upstream thalamic populations and computational modeling provide evidence that the tuning of PoSub-FS cells has a local origin. These findings support the notion that the equivalence of neuronal tuning between excitatory and inhibitory cell populations is an intrinsic property of local cortical networks.

兴奋和抑制之间的相互作用决定了皮质表征的保真度。兴奋性神经元的感受野通常会根据编码特征进行微调，但抑制性神经元的调节原理仍然难以捉摸。在这项研究中，我们记录了小鼠枕后 (PoSub) 中的神经元群体，其中大多数兴奋性神经元是头向 (HD) 细胞。我们发现，最大的一类皮层抑制神经元——快速尖峰（FS）细胞的调节范围很广，并且经常呈放射状对称。通过使用傅立叶变换分解调谐曲线，我们确定了 PoSub-FS 和 PoSub-HD 细胞群之间的调谐等效性。此外，上游丘脑群体的记录、光遗传学操作和计算模型提供了PoSub-FS细胞的调节具有局部起源的证据。这些发现支持这样的观点：兴奋性细胞群和抑制性细胞群之间神经元调节的等效性是局部皮质网络的固有属性。