Synchronization of Isolated Downstates (K-Complexes) May Be Caused by Cortically-Induced Disruption of Thalamic Spindling
Figure 9
Currents and conductances underlying KCs.
A, A spontaneous KC (same KC as in Figure 4), B, a KC evoked by depolarizing all RE neurons (same KC as in Figure 7A), or C, a KC evoked by stimulating 6 PY neurons projecting to all RE neurons (same KC as in Figure 7B), all show a drop in PY spiking (“KC”), and in RE and TC spindling (red asterisks). The orange box in B and the black box in C indicate the length of the applied RE depolarization or PY stimulation, respectively. In all three cases, these characteristics of the KC were preceded by RE IT inactivation dropping towards zero (RE IT h, purple asterisks), indicating greater inactivation. A decrease in PY to RE currents and a decrease in TC IT accompanied this RE IT inactivation drop. During the KC, an increase in RE IT h indicates greater deinactivation (green asterisks), and rebound spindling.