Differential roles of sleep spindles and sleep slow oscillations in memory consolidation
Fig 5
The role of slow oscillation during two-sequence learning.
a) The model simulated transitions from awake to N3 sleep, and to awake again. Orange bar represents the duration of training of each sequence (top: Seq1;bottom: Seq2).b) A cartoon of the sequential network stimulation to generate two sequences. The duration of stimulation was 10ms for each group of neurons. The delay between subsequent stimuli of two groups was 5ms. Each group includes five neurons.c) A characteristic example of test and training of Seq1 (“A1B1C1D1E1”). The test was stimulating only at group A1.d) Test and training of Seq2 (“E2D2C2B2A2”). The test was stimulating only at group E2. The Seq1 and Seq2 started at neuron #200 and #300, respectively.e) The bar plots of performance for Seq1 and Seq2 during different test sessions. Error bars indicate SEM.f) A characteristic example of the sequences replay during slow oscillations.g) The bar plots of the total replayed Seq1 (top) and Seq2 (bottom) during N3 sleep in correct and reverse order. Error bars indicate SEM. The correct and reversed orders for Seq1 were “A1B1C1D1E1” and “E1d1C1B1A1”, respectively. The correct and reversed orders for Seq2 were “E2D2C2B2A2” and “A2B2C2D2E2”, respectively.h) The change of synaptic weights relative to the initial values after training (left) and after N3 sleep (right). Note that synaptic weights between neurons in the direction of Seq1 activation (red box) and Seq2 (magenta box) were both enhanced due to the training (left) but the effect decayed for Seq2 after N3 (right).i) The synaptic weights associated with Seq1 (red) were progressively increased during N3, while those associated with Seq2 (magenta) were decreased during N3 due to the interaction from the reactivation of Seq1. When Seq2 was trained alone (no interference) in the same experimental conditions, synaptic weights associated with Seq2 increased during N3 (black). The patch error bar represents standard deviation. * p<0.05, ** p<0.01, *** p<0.001. N.S. represents no significant difference.