Synchronization of Isolated Downstates (K-Complexes) May Be Caused by Cortically-Induced Disruption of Thalamic Spindling
Figure 6
Parametric modulation of spontaneous KC frequency by changing the projection from PY to RE.
A, Increasing the number of PY neurons projecting to all RE neurons increased the number of spontaneous KCs in a near linear fashion. B, In contrast, increasing the strength of projections from PY neurons to RE neurons had little effect until a threshold strength was reached and the system began oscillating almost continuously (i.e., generated SOs rather than KCs). In A, the PY to RE configuration schematic on the left illustrates one PY cell projecting to all RE neurons, while each of the remaining PY neurons maintain a projection to 5 RE neurons (as in Figure 3C). The schematic on the right shows how the projection pattern changes with the addition of a second PY neuron projecting to all RE neurons. In B, the schematic on the left illustrates the original model configuration (as in Figure 3B), while the right schematic shows the increasing strength of PY to RE connections. For each value on the x-axis, 10 simulations of 200 s with different random seeds were run. The number of spontaneous KCs was calculated for each run; each value represents the average number of KCs per minute in the 10 runs ± SEM. The black arrow marks 10 PY neurons projecting to all RE neurons while the red arrow marks the original connectivity with a strength of 1 µS between PY and RE neurons.