The spatial scale of somatostatin subnetworks increases from sensory to association cortex.

Incoming signals interact with rich, ongoing population activity dynamics in cortical circuits. These intrinsic dynamics are the consequence of interactions among local excitatory and inhibitory neurons and affect inter-region communication and information coding. It is unclear whether specializations in the patterns of interactions among excitatory and inhibitory neurons underlie systematic differences in activity dynamics across the cortex. Here, in mice, we compare the functional interactions among somatostatin (SOM)-expressing inhibitory interneurons and the rest of the neural population in auditory cortex (AC), a sensory region of the cortex, and posterior parietal cortex (PPC), an association region. The spatial structure of shared variability among SOM and non-SOM neurons differs across regions: correlations decay rapidly with distance in AC but not in PPC. However, in both regions, activity of SOM neurons is more highly correlated than non-SOM neurons' activity. Our results imply both generalization and specialization in the functional structure of inhibitory subnetworks across the cortex. [Display omitted] • In vivo imaging of somatostatin inhibitory neurons in auditory and parietal cortices • SOM neurons in both regions form highly coordinated subnetworks • The spatial scale of shared variability across neurons is wider in parietal cortex Khoury et al. show that somatostatin-expressing interneurons form highly coordinated subnetworks in both sensory and association cortices. However, the spatial scale of these subnetworks is significantly broader in association cortex relative to sensory cortex, implying area-specific specialization in the structure of inhibitory subnetworks. [ABSTRACT FROM AUTHOR]