Optogenetic disruption of neural dynamics in the prefrontal cortex impaired spatial learning

Cortical neural activity is highly dynamical at several temporal scales, property that has been postulated to be critical for the emergence of specific patterns supporting cognitive operations. During spatial learning, task-associated activity patterns gradually develop in the medial prefrontal cortex (mPFC) as the subject acquires experience. If neural activity dynamics is required in the mPFC for spatial learning is still unclear. Here we show that optogenetic entrainment of neural activity the mPFC disrupted local oscillatory and single-neuron dynamics. When applied during spatial training, optogenetic entrainment impaired behavioral performance and navigation strategy progression, a hallmark of spatial learning supported by the mPFC. Also, optogenetic entrainment blocked the emergence of learning-related activity patterns such as cross-frequency coupling and firing patterns signaling efficient goal approaching. Importantly, during memory retrieval, training-stimulated mice showed impaired performance in the absence of optogenetic stimulation. This evidence show that neural activity dynamics in the mPFC is crucial for spatial learning.