Induction of long-term potentiation leads to increased reliability of evoked neocortical spindles in vivo

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

“…A slow oscillation upstate can be triggered by a few excitatory quantal events, which are likely to originate from recently potentiated synaptic connections within a network that has been lately involved in a particular task (Timofeev et al, 2000;Ribeiro et al, 2004). This cortical upstate is able to run a sequence of highly synchronous spindles that are known to occur more likely at previously potentiated synapses (Werk at al., 2005). These spindles will lead to further strengthening of connections between synchronously firing cells, according to a Hebbian rule; however, because the slow oscillation is a traveling wave , only a limited number of cells are firing together in a certain time interval during a spindle.…”

Intracortical Augmenting Responses in Networks of Reduced Compartmental Models of Tufted Layer 5 Cells

“…S6 for details). Thus it is suggested that the reported AR characteristics within the alpha range 7-12 Hz (such as that reported by Castro-Alamancos and Connors 1996a), commonly the relevant range because it corresponds to spindle oscillations (Khazipov et al 2004;Werk et al 2005Werk et al , 2006, is not particularly sensitive to the exact value of GABA-B receptor decay time.…”

“…First, layer 5 cells have been closely linked to longterm potentiation and depression following tetanization of callosal connection in sensorimotor areas (Chapman et al 1998), as well as to the generation of spindle activity during periods of sleep and awake immobility (Werk et al 2005(Werk et al , 2006. Although such plasticity phenomena and the ensuing spreading activity are likely to require full thalamocortical interaction (Steriade and Timofeev 2003), as well as modeling other pyramidal cell types of layer 5 (Christophe et al 2005), the current work represents a first-step effort in understanding resonance phenomena in layer 5 networks that might facilitate the production of potentiation.…”

“…Augmentation has been reported to occur selectively in vivo within specific stimulus frequency bands in the alpha frequency range, at about 10 Hz or possibly wider at about 3-15 Hz (Chrochet et al 2006;Timofeev et al 2002). Oscillations at these frequencies are thought to play a role in long-term potentiation (Werk et al 2005) and depression in sensorimotor cortex of rats (Werk et al 2006). Although considered earlier to be of a mainly thalamic origin (Morison and Dempsey 1943), it became clear that ARs can be generated cortically (Castro-Alamancos and Connors 1996a,b;Morin and Steriade 1981) as well as thalamically (Gernier et al 1998; because ARs could occur after thalamic lesioning by stimulating the white matter of callosally projecting fibers .…”

Sleep spindles and cognition in depression

“…On the systems levels, neocortical medial temporal lobe (including hippocampus) activation and connectivity are observed during sleep spindle activity (Schabus et al 2007;Andrade et al, 2011). During sleep slow waves, the occurrence and timing of of sleep spindles appears most vital for the coordination hippocampal and cortical activity to reactivate hippocampal memory representations for their integration into cortical networks (Staresina et al, 2015, Buzsáki, 2015, Ayoub et al, 2012, Takeuchi et al 2016 as they induce synaptic plasticity (Werk et al, 2005) in cortical dendrites (Seibt et al 2017) that likely underlie memory processing and cognitive development. These processes surrounding sleep spindle activity thus also mark 'offline' periods of deeper sleep in which the brain suppresses processing of environmental cues and has increased thresholds for arousal (DangVu et al, 2011).…”