Topic: UP and DOWN states

During NREM sleep, the brain is in a self-organized excitable regime in which alternations between spiking and near cessation of spiking propagate along the forebrain, termed slow oscillations (SOs) or UP and DOWN states in the neocortex, and sharpwave-ripples (SPW-Rs) in the hippocampus (Levenstein 2019). Both gain and loss of function studies have demonstrated the importance of tight temporal coordination between SOs and SPW-Rs for systems consolidation. However, where and how this coordination is spontaneously achieved is unknown, despite being essential for understanding whole-brain mechan

Synaptic mechanisms of memory consolidation in the human brain remain largely unexplored. During slow wave sleep, which is critical for memory formation, neocortical neurons exhibit characteristic membrane potential oscillations known as UP and DOWN states. We demonstrate that sleep-like UP and DOWN states modulate axonal action potentials and enhance synaptic transmission between human layer 2 & 3 pyramidal neurons. In the cortical microcircuit, synaptic enhancement by synchronous UP and DOWN states gives rise to efficient recruitment of action potentials in postsynaptic neurons, which in tur