Efficient enhancement of information in the prefrontal cortex during the presence of reward predicting stimuli

• Published in: PloS one Vol. 12; no. 12; p. e0188579
• Main Authors: Mininni, Camilo J, Caiafa, César F, Zanutto, B Silvano, Tseng, Kuei Y, Lew, Sergio E
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 13.12.2017; Public Library of Science (PLoS)
• Subjects: Action Potentials - physiology; Analysis; Animals; Biology and Life Sciences; Brain; Computer and Information Sciences; Cues; Decision making; Dopamine; Entropy; Firing pattern; Firing rate; Go/no-go discrimination learning; Health aspects; Male; Medicine and Health Sciences; Memory; Neurons; Neurosciences; Physical Sciences; Population; Prefrontal cortex; Prefrontal Cortex - physiology; Rats; Rats, Long-Evans; Reinforcement; Reward; Rodents; Short term memory; Stimuli; Stimuli (Psychology); Synaptic strength
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0188579

The prefrontal cortex (PFC) is a key brain structure for decision making, behavioural flexibility and working memory. Neurons in PFC encode relevant stimuli through changes in their firing rate, although the metabolic cost of spiking activity puts strong constrains to neural codes based on firing rate modulation. Thus, how PFC neural populations code relevant information in an efficient way is not clearly understood. To address this issue we made single unit recordings in the PFC of rats performing a GO/NOGO discrimination task and analysed how entropy between pairs of neurons changes during cue presentation. We found that entropy rises only during reward-predicting cues. Moreover, this change in entropy occurred along an increase in the efficiency of the whole process. We studied possible mechanisms behind the efficient gain in entropy by means of a two neuron leaky integrate-and-fire model, and found that a precise relationship between synaptic efficacy and firing rate is required to explain the experimentally observed results.