A sleeping brain is still hard at work

PHILADELPHIA, Feb. 12 (UPI) -- U.S.-led research is providing strong support for the idea that one of the key functions of sleep is the consolidation of memories.

University of Pennsylvania School of Medicine researchers say although sleep is thought to facilitate memory and learning, the molecular links between sleep and synaptic plasticity aren't well understood. Ocular dominance plasticity -- in which one eye can become dominant if the other eye is blocked -- is a classic model of experience-dependent cortical plasticity that allows scientists to follow specific changes in the visual cortex in response to the occlusion of one eye.

"We have shown that ODP is consolidated by sleep," said senior study author Assistant Professor Marcos Frank.

Frank and colleagues performed a series of experiments designed to test the hypothesis and found sleep consolidates ODP primarily by strengthening cortical responses to stimulation of the non-deprived eye. They discovered certain receptors and proteins mediated intracellular cascades and were critical components of the cellular machinery required for sleep-dependent consolidation of ODP, and their activation during sleep promoted synaptic strengthening.

The study is reported in the journal Neuron.