Pattern-Specific Associative Long-Term Potentiation Induced by a Sleep Spindle-Related Spike Train

Abstract

Spindles are non-rapid eye movement (non-REM) sleep EEG rhythms (7-14 Hz) that occur independently or in association with slow oscillations (0.6 -0.8 Hz). Despite their proposed function in learning and memory, their role in synaptic plasticity is essentially unknown. We studied the ability of a neuronal firing pattern underlying spindles in vivo to induce synaptic plasticity in neocortical pyramidal cells in vitro. A spindle stimulation pattern (SSP) was extracted from a slow oscillation upstate that was recorded in a cat anesthetized with ketamine-xylazine, which is known to induce a sleep-like state. To mimic the recurrence of spindles grouped by the slow oscillation, the SSP was repeated every 1.

Sleep spindles in midday naps enhance learning in preschool children

“…identified for this age range. Nonetheless, slow and fast spindles have been associated with hippocampal reactivation and plasticity (34)(35)(36)(37)(38), and studies in young adults have found an association between spindles and learning (24,39,40). Likewise, we posit that in preschool children, spindles may mark hippocampal-neocortical interactions, a process underlying the stabilization and consolidation of the memory.…”

Sleep spindles are locally modulated by training on a brain–computer interface

“…Increasingly, sleep spindles, one of the most prominent features of NREM, have been implicated in these plastic processes (5,7,8,17,29). It has been postulated that spindles facilitate synaptic plasticity in cortical cells via calcium-dependent mechanisms (11), and it has been shown that cortical stimulation at the spindle frequency increases synaptic plasticity (30). If spindles are truly the carriers of memory consolidation, then they must act specifically on local circuits.…”

Elevated Sleep Spindle Density after Learning or after Retrieval in Rats

“…It has been proposed that spindle activity sets the conditions for synaptic changes by favoring calcium entry into the cell and initiation of plasticity-related intracellular cascades (Sejnowski and Destexhe, 2000;Lisman et al, 2002;Benington and Frank, 2003). Indeed, a neuronal firing pattern corresponding to spindle oscillations in vivo has been reported recently to induce synaptic potentiation in neocortical pyramidal cells in vitro (Rosanova and Ulrich, 2005). Thus, increased density of cortical spindles can promote synaptic reinforcement in networks that have been actively engaged during learning.…”

“…Previous studies had focused on the rapid eye movement (REM) phase; slow-wave sleep (SWS) has been strongly implicated now, as well (for review, see Gais and Born, 2004;Rauchs et al, 2005;Walker and Stickgold, 2006). Sleep spindles, 12-15 Hz oscillations superimposed on slow waves , may promote neural plasticity underlying learning and memory (Steriade and Timofeev, 2003;Rosanova and Ulrich, 2005). Moreover, there is recent evidence for an increase in spindle density after verbal learning Clemens et al, 2005) or motor learning (Smith and MacNeill, 1994;Meier-Koll et al, 1999;Fogel et al, 2002).…”