title: Sleep and plasticity.
abstract: While there is ample agreement that the cognitive role of sleep is explained by sleep-dependent synaptic changes, consensus is yet to be established as to the nature of these changes. Some researchers believe that sleep promotes global synaptic downscaling, leading to a non-Hebbian reset of synaptic weights that is putatively necessary for the acquisition of new memories during ensuing waking. Other investigators propose that sleep also triggers experience-dependent, Hebbian synaptic upscaling able to consolidate recently acquired memories. Here, I review the molecular and physiological evidence supporting these views, with an emphasis on the calcium signaling pathway. I argue that the available data are consistent with sleep promoting experience-dependent synaptic embossing, understood as the simultaneous non-Hebbian downscaling and Hebbian upscaling of separate but complementary sets of synapses, heterogeneously activated at the time of memory encoding and therefore differentially affected by sleep.
authors.affiliation: Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Rio Grande do Norte, Brazil. sidartaribeiro@neuro.ufrn.br
authors.forename: Sidarta
authors.initials: S
authors.lastname: Ribeiro
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology; D006801:Humans; D009473:Neuronal Plasticity / Q000502:physiology*; D012890:Sleep / Q000502:physiology*; D013569:Synapses / Q000502:physiology