How sleep helps us remember - and forget

Scimex: Sleeping plays an important role in forming lasting memories, but controversy remains over whether the sleeping brain helps to create these memories by deleting unnecessary connections or by strengthening important ones. Now new animal research suggests that both processes occur during sleep. Sleep is important for long lasting memories, particularly during this exam season. Research publishing in PLOS Computational Biology suggests that sleeping triggers the synapses in our brain to both strengthen and weaken, which prompts the forgetting, strengthening or modification of our memories in a process known as long-term potentiation (LTP).

Researchers led by Sidarta Ribeiro at the Brain Institute of the Federal University of Rio Grande do Norte, Brazil, measured the levels of a protein related to LTP during the sleep cycle of rats. The authors then used the data to build models of sleep-dependent synaptic plasticity.
The results show that sleep can have completely different effects depending on whether LTP is present or not. A lack of LTP leads to memory erasure, while the presence of LTP can either strengthen memories or prompt the emergence of new ones.
The research provides an empirical and theoretical framework to understand the mechanisms underlying the complex role of sleep for learning, which involves selective remembering as well as creativity.