Temporal progression along discrete coding states during decision-making in the mouse gustatory cortex

摘要

The mouse gustatory cortex (GC) is involved in taste-guided decision-making in addition to sensory processing. Rodent GC exhibits metastable neural dynamics during ongoing and stimulus-evoked activity, but how these dynamics evolve in the context of a taste-based decision-making task remains unclear. Here we employ analytical and modeling approaches to i) extract metastable dynamics in ensemble spiking activity recorded from the GC of mice performing a perceptual decision-making task; ii) investigate the computational mechanisms underlying GC metastability in this task; and iii) establish a relationship between GC dynamics and behavioral performance. Our results show that activity in GC during perceptual decision-making is metastable and that this metastability may serve as a substrate for sequentially encoding sensory, abstract cue, and decision information over time. Perturbations of the model's metastable dynamics indicate that boosting inhibition in different coding epochs differentially impacts network performance, explaining a counterintuitive effect of GC optogenetic silencing on mouse behavior. Author summaryNeural circuits can operate in a dynamic regime characterized by sequences of metastable states. Each state can last for hundreds of ms and is described by correlated spiking activity across ensembles of neurons. Metastable dynamics have been shown to play a role in representing sensory information and cognitive signals. In this article, we demonstrate that activity in the gustatory cortex of mice engaged in a decision-making task is metastable. We found that some metastable states are associated with the perception of taste, while others are associated with decision processes. This neural activity, and the behavioral performance sustained by it, can be explained by a metastable network model comprising connected ensembles of spiking neurons. When mimicking optogenetic silencing conducted in previous experiments, our model simulations reveal the link between the disruption of metastable state sequences and the behavioral impairment due to the optogenetic manipulation. Altogether, our results reveal the importance of metastable states in mediating taste perception related to task performance.