Figure 6.

Effect of selective removal of postsynaptic receptors at cortical and thalamic synapses on the simulated slow oscillation. (a(i)) Simulated slow oscillation in a TC neuron with the CT AMPAR blocked shows groups of delta oscillation in the DOWN state. (ii) When the mGlu-R1 component of the CT synapses on TC neurons is blocked, the simulated slow oscillation in TC neuron is almost fully abolished and replaced by nearly continuous delta oscillation. (b(i)) Reduction in the number of synchronous UP and DOWN state transitions between NRT and TC neurons is observed when the CT AMPARs on NRT neurons are blocked. Also, the firing of the NRT neurons becomes much less intense (cf. figure 5a). (ii) Removal of the mGluR1 component of the CT synapse of NRT neurons brings both TC and NRT neurons into a permanent UP state with synchronized subthreshold oscillation and intermittent firing, respectively (normal g_AMPA). A reduction in g_AMPA of the CT synapses on both TC and NRT neurons restores the slow oscillation (decreased g_AMPA). (c) Block of the AMPARs on the thalamic afferent to layer 4 neurons leads to an almost complete loss of global synchrony across the TC network. At the same time, two separate synchronies emerge: one between layer 4 and layer 6 neurons and another between TC and NRT neurons. These can occur almost simultaneously (i) or clearly separated in time (ii).