Augmenting hippocampal–prefrontal neuronal synchrony during sleep enhances memory consolidation in humans

Sleep helps stabilize long-term memories, for example declarative hippocampal-dependent memories have been suggested to benefit from synchronization of neuronal activity in hippocampus and cortex during NREM sleep. Working with epilepsy patients implanted with intracranial electrodes for clinical reasons, we studied this process with single neuron resolution. We used electrical pulses in the prefrontal cortex, precisely timed with slow-wave activities in the hippocampal formation, to tie spindle activity and coupling of sleep oscillations across the brain to improved memory performance.