PT  - JOURNAL ARTICLE
AU  - Moises Arriaga
AU  - Edward B. Han
TI  - Structured Inhibitory Activity Dynamics During Learning
AID  - 10.1101/566257
DP  - 2019 Jan 01
TA  - bioRxiv
PG  - 566257
4099  - http://biorxiv.org/content/early/2019/04/27/566257.short
4100  - http://biorxiv.org/content/early/2019/04/27/566257.full
AB  - Inhibition plays a powerful role in regulating network excitation and plasticity; however, the relationship between learning and inhibitory activity dynamics remains unclear. Furthermore, do individual interneurons play consistent functional roles during learning or is their activity driven stochastically? Using two-photon calcium imaging, we recorded hippocampal CA1 somatostatin-expressing interneurons as mice learned a virtual reality task in new visual contexts. We found strong initial suppression of inhibitory activity that gradually diminished as animals learned, while blocking learning using a “no task” environment prevented the recovery of inhibitory activity. Although the magnitude of suppression differed across the population, each interneuron showed consistent levels of activity modulation during learning across multiple novel environments. This work reveals learning-related dynamic inhibition suppression, during which inhibitory networks display stable and consistent activity structure. This functional inhibitory circuit architecture suggests that individual interneurons play specialized and stereotyped roles during learning, perhaps by differentially regulating excitatory neuron ensembles.