Showing papers on "Local sleep published in 2010"
TL;DR: Sleep has been identified as a state that optimizes the consolidation of newly acquired information in memory, depending on the specific conditions of learning and the timing of sleep, through specific patterns of neuromodulatory activity and electric field potential oscillations.
Abstract: Sleep improves the consolidation of both declarative and non-declarative memories. Diekelmann and Born discuss the potential mechanisms through which slow wave sleep and rapid eye movement sleep support system and synaptic consolidation. Sleep has been identified as a state that optimizes the consolidation of newly acquired information in memory, depending on the specific conditions of learning and the timing of sleep. Consolidation during sleep promotes both quantitative and qualitative changes of memory representations. Through specific patterns of neuromodulatory activity and electric field potential oscillations, slow-wave sleep (SWS) and rapid eye movement (REM) sleep support system consolidation and synaptic consolidation, respectively. During SWS, slow oscillations, spindles and ripples — at minimum cholinergic activity — coordinate the re-activation and redistribution of hippocampus-dependent memories to neocortical sites, whereas during REM sleep, local increases in plasticity-related immediate-early gene activity — at high cholinergic and theta activity — might favour the subsequent synaptic consolidation of memories in the cortex.
2,983 citations
TL;DR: The evidence for use-dependent modulation of neocortical activity during sleep is compelling and provides novel insights into sleep function, however, local changes in neocortex are generally expressed on a background of global sleep.
Abstract: Purpose of review Regions of the neocortex most strongly activated during waking exhibit increased sleep intensity during subsequent sleep. The novel concept that aspects of sleep homeostasis are determined locally in the cortex contrasts with the established views that global changes in neocortical activity during sleep are achieved through inhibition of ascending arousal systems that originate in the brainstem and hypothalamus. Recent findings Experiments in animals and humans document asymmetries in neocortical electroencephalogram (EEG) slow-wave activity (SWA), a marker of homeostatic sleep need, as a result of functional activity during waking. In addition to local, use-dependent augmentation of EEG SWA and evoked potentials, expression of plasticity-related genes and of sleep-regulatory cytokines and neuromodulators have been shown to be elevated in a use-dependent manner in neocortex. The functional consequences of local sleep are hypothesized to involve regulation of synaptic plasticity, synaptic homeostasis and energy balance. Summary The evidence for use-dependent modulation of neocortical activity during sleep is compelling and provides novel insights into sleep function. However, local changes in neocortex are generally expressed on a background of global sleep. It remains to be determined if events initiated in the cortex have global sleep-promoting effects and how neocortical and hypothalamic mechanisms of sleep control interact.
25 citations
TL;DR: Overall, chicks that learned the spatial task slept significantly more than chicks that were exposed to the experimental paradigm but did not learn the task, suggesting that the Mo-Un sleep pattern showed by experimental chicks is a type of local sleep associated with a process of functional recovery and/or with consolidation of memory in the right hemisphere, which would be mainly engaged during training trials.
Abstract: During sleep, domestic chicks (Gallus gallus) show brief and transient periods during which one eye is open while the other remains shut. Electrophysiological recordings showed that the hemisphere contralateral to the open eye exhibited an EEG with fast waves typical of wakefulness, whereas the hemisphere contralateral to the closed eye exhibited an electroencephalogram (EEG) typical of slow-wave sleep. We investigated the time spent in sleep and in monocular-unihemispheric sleep (Mo-Un sleep) following the learning of a spatial discrimination task. A group of experimental chicks from days 8 to 11 post-hatching were trained singly to select one container among four, having a hole on the top (making food available) and positioned in a corner of a rectangular arena. Chicks of the control group did not learn the task because all four containers had a hole on the top and therefore chicks could randomly select any one of them. Experimental and control chicks underwent the same number of trials. Experimental chicks had more total time spent sleeping than control chicks. Experimental chicks spent more time in left Mo-Un sleep, which would be connected with a dominance of the right hemisphere during learning trials. Control chicks showed no eye closure bias at days 8 and 9; however, a slight bias for more right eye closure at days 10 and 11 was observed, suggesting that there was an absence of hemispheric dominance during the first 2 days of control trials and a dominance of the right hemisphere during the last 2 days of control trials. Overall, chicks that learned the spatial task slept significantly more than chicks that were exposed to the experimental paradigm but did not learn the task. This suggests that the Mo-Un sleep pattern showed by experimental chicks is a type of local sleep associated with a process of functional recovery and/or with consolidation of memory in the right hemisphere, which would be mainly engaged during training trials.
16 citations