Behavioral state and stimulus strength regulate the role of somatostatin interneurons in stabilizing network activity

We investigated the role of somatostatin-expressing (SST) interneurons in inhibition stabilization within mouse primary visual cortex. By selectively blocking glutamatergic inputs to SST cells, we observed paradoxical facilitation of SST activity with increasing stimulus contrast and arousal—a hallmark of inhibition stabilization. Our computational modeling revealed that higher sensory input and arousal drive the network toward regimes where other interneuron classes cannot maintain stability alone. We demonstrate that SST cells' contribution to cortical processing is state-dependent, becoming increasingly critical as input strength and behavioral arousal increase, thereby enabling stable sensory encoding across diverse contexts.

本研究探究了表达生长抑素（SST）的中间神经元在小鼠初级视觉皮层抑制稳定机制中的作用。通过选择性阻断SST细胞的谷氨酸能输入，我们观察到随着刺激对比度与觉醒水平提升，SST神经元活性出现反常易化——这正是抑制稳定的标志性特征。我们的计算建模研究表明，更强的感觉输入与觉醒状态会推动神经网络进入其他中间神经元亚型无法单独维持稳定的调控区间。本研究证实，SST细胞对皮层处理的贡献具有状态依赖性：随着输入强度与行为觉醒水平提升，其作用愈发关键，从而使得多样情境下的稳定感觉编码成为可能。