Stable sequential dynamics in prefrontal cortex represents subjective estimation of time

Stable sequential dynamics in prefrontalcortex represents subjective estimationof time

Yiting Li1,2†, Wenqu Yin1†, Xin Wang2, Jiawen Li1,3, Shanglin Zhou4, Chaolin Ma1*,Peng Yuan2*, Baoming Li1,5*

Abstract

Time estimation is an essential prerequisite underlying various cognitive functions.Previous studies identified ‘sequential firing’ and ‘activity ramps’ as the primary neuron activitypatterns in the medial frontal cortex (mPFC) that could convey information regarding time.However, the relationship between these patterns and the timing behavior has not been fullyunderstood. In this study, we utilized in vivo calcium imaging of mPFC in rats performing a timingtask. We observed cells that showed selective activation at trial start, end, or during the timinginterval. By aligning long-term time-lapse datasets, we discovered that sequential patterns oftime coding were stable over weeks, while cells coding for trial start or end showed constantdynamism. Furthermore, with a novel behavior design that allowed the animal to determineindividual trial interval, we were able to demonstrate that real-time adjustment in the sequenceprocession speed closely tracked the trial-to-trial interval variations. And errors in the rats’ timingbehavior can be primarily attributed to the premature ending of the time sequence. Together,our data suggest that sequential activity maybe a stable neural substrate that represents timeunder physiological conditions. Furthermore, our results imply the existence of a unique cell typein the mPFC that participates in the time-related sequences. Future characterization of this celltype could provide important insights in the neural mechanism of timing and related cognitivefunctions.

原文链接：https://elifesciences.org/articles/96603