Medial prefrontal cortex population activity is plastic irrespective of learning

Singh, Abhinav; Peyrache, Adrien; Humphries, Mark D.

Abstract

The prefrontal cortex is thought to learn the relationships between actions and their outcomes. But little is known about what changes to population activity in prefrontal cortex are specific to learning these relationships. Here we characterise the plasticity of population activity in the medial prefrontal cortex of male rats learning rules on a Y-maze. First, we show that the population always changes its patterns of joint activity between the periods of sleep either side of a training session on the maze, irrespective of successful rule learning during training. Next, by comparing the structure of population activity in sleep and training, we show that this population plasticity differs between learning and non-learning sessions. In learning sessions, the changes in population activity in post-training sleep incorporate the changes to the population activity during training on the maze. In non-learning sessions, the changes in sleep and training are unrelated. Finally, we show evidence that the non-learning and learning forms of population plasticity are driven by different neuron-level changes, with the non-learning form entirely accounted for by independent changes to the excitability of individual neurons, and the learning form also including changes to firing rate couplings between neurons. Collectively, our results suggest two different forms of population plasticity in prefrontal cortex during the learning of action-outcome relationships, one a persistent change in population activity structure decoupled from overt rule-learning, the other a directional change driven by feedback during behaviour.

Citation

Singh, A., Peyrache, A., & Humphries, M. D. (2019). Medial prefrontal cortex population activity is plastic irrespective of learning. Journal of Neuroscience, 39(18), 3470-3483. https://doi.org/10.1523/JNEUROSCI.1370-17.2019

• Journal Article Type: Article
• Acceptance Date: Jan 11, 2019
• Online Publication Date: Feb 27, 2019
• Publication Date: May 1, 2019
• Deposit Date: Jan 16, 2019
• Publicly Available Date: Aug 28, 2019
• Journal: Journal of Neuroscience
• Electronic ISSN: 1529-2401
• Publisher: Society for Neuroscience
• Peer Reviewed: Peer Reviewed
• Volume: 39
• Issue: 18
• Pages: 3470-3483
• DOI: https://doi.org/10.1523/JNEUROSCI.1370-17.2019
• Keywords: General Neuroscience
• Public URL: https://nottingham-repository.worktribe.com/output/1476284
• Contract Date: Jan 16, 2019