Table 4 Free parameters
Name | Description | Biological Range | Optimal Value | Reference |
|---|---|---|---|---|
Slope %Syn | Slope of fraction of synapses disappearing/week | Max 0.075%/week, on top of neuronal loss | 0.004 | [94] |
Slope %Neuron | Slope of neurons eliminated/week | Max 0.5%/week, leads to 50% neuron loss in 100 weeks | 0.025 | [78] |
ACh deficit | Size of the cholinergic NBasalis deficit | Range 5-50% loss | 0.175 | |
5-HT6 effect | Relation between 5-HT6 inhibition and free DA, ACH and NE increase | Maximum 0.20 | 0.025 | [33] |
DA increase in 12 wk placebo | DA surge from reward circuit that simulates placebo effect | Maximal 20% (tracer displacement in volunteers) | 0.075 | |
Rel α 7 vs. α 4β 2 nACh-R effect | Relative effect of α7 over α 4β 2 nACh-R mediated effects | Depends upon dose and nature of enhancement Range 0.4-2.0 | 2 | [97] |
AChE-I effect on M1 receptor activation | AChE-I increases M1 mACh-R activation level to make pyramidal cells more excitable | Maximal change in membrane resting potential -8 mV (depolarizing) | 0.075/8 mg Gal or equiv | [98] |