Figure 6

Proposed control system block diagram representation. Synaptic activity resulting from the glutamatergic signaling of NMDARs is controlled via a dual-action composite controller (blue box). The activity subcontroller of this composite controller translocates NMDARs from an extrasynaptic pool to the synapse in response to deviations from the explicit set point number of unblocked synaptic NMDARs. The activity of this controller is also modulated by the alcohol level. The density subcontroller removes unblocked NMDARs from the synapse according to the deviation in total NMDARs (blocked and unblocked) from the set point. The combined activity of the two subcontrollers contributes to a net relocation that alters the number of unblocked synaptic NMDARs. Unblocked NMDARs can also be blocked by alcohol. Measurements of the number of unblocked NMDARs and the total number of synaptic NMDARs are then returned to the controller via a negative feedback loop.