Sleep promotes the formation of dendritic filopodia and spines near learning-inactive existing spines

Significance Sleep contributes to long-term memory formation after learning, but underlying mechanisms remain unclear. We found that post-learning sleep promoted the formation of dendritic filopodia and spines clustered with learning-inactive existing spines. A fraction of these filopodia was converted into new spines over extended periods of time. These findings provide insights into the role of post-learning sleep in regulating the number and location of new synapses via promoting dendritic filopodial formation.