Figure 4.

SPW-R stabilization depends on the timing of the stimulation in CA1 but not in CA3. (A) In the original stimulation paradigm (upper trace, red) stimulations were triggered 150 ms after spontaneous SPW-R. To investigate the effect of stimulation timing, repetitive stimulations were performed during spontaneous SPW-R in a second control paradigm (lower trace, orange). (B) The stabilizing effect of the repetitive stimulation performed 150 ms after a spontaneous event (red; p < 0.05, n = 8) abolished by stimulating during a spontaneous SPW-R in CA1 (orange; median 0.96, 25^th 0.85, 75^th 1.07, n = 7, p < 0.05 between both conditions). This difference was absent in the CA3 (CA3a: median 1.01, 25^th 0.93, 75^th 1.07; CA3b: median 1.03, 25^th 0.84, 75^th 1.12) region. (C) Spontaneously occurring SPW-R showed the same effect as evoked events: In CA1 the stabilizing effect of repetitive stimulation 150 ms after spontaneous events (dark gray; p < 0.01, n = 10) was abolished by stimulating during spontaneous SPW-R (light gray; median 1.01, 25^th 0.93, 75^th 1.07, n = 8, p < 0.001 between both conditions) but not in CA3 (CA3a: median 1.02, 25^th 0.97, 75^th 1.05; CA3b: median 1.04, 25^th 0.99, 75^th 1.12). “*” means that the finding is significant (p < 0.05).