Miscellaneous model details: 1) The two starting cases can be controlled by pushing one of two buttons in the "Morphology and Spine neck resistivity" control panel about a third of the way up from the bottom: a) dendrite diam=2 (look for the diam2_dendrite_gbar_ca) This is the original dendrite length and ion channels max conductance configuration for the paper. The Na and K excitability (maximum conductances) were raised to a level comfortably above where reliably propagated bAPs occur (When the conductace is lowered by multiplying by 0.4 the bAPs decrement as they propagate. Starting from a multiplying "factor=0.5" in an init.hoc morpohology control panel, lowering to "factor=0.2" accomplishes this .4 drop ). The calcium maximum conductances were set to where a single bAP accumulated a peak of 1 uM Ca (suggested by Higley) in an uninhibited spine head. The calcium currents do not significantly effect the voltage trajectory so this setting is arbitrary in regards to the voltage trace. b) dendrite diam=.7 (look for the diamp7_dendrite_gbar_ca) The same statements under a) above apply except that the K density (K_DR mechanism "kv") was boosted to counteract additional excitability of smaller sized membrane which fires a chain of APs in the chloride reversal potential = -40 mV numerical experiment. (The real experiments do not have a train of APs in this case). --- On the length of the dendrite choice: We use the dendrite L=600 micron version to avoid bAP peaks growing per distance from the soma (confounding the studies of inhibition) as occur in the L=200 case. In L=200 the bAP peaks grow as they propagate through the distances that the spines are placed, close to the end of the cylinder. We assume in the real neurons decreasing sodium channels or increasing K channels likely maintain constant height of bAPs as they propagate since experimentally the peak Ca signals in spines are distance independent (Figure S3c). We could have used maximum conductances that varied as a function of distance in the model instead of the longer dendrite. --- The supplemental graph panels show changes in the activation of ca (vertical) and changes in the reversal potential of gabaa (horizontal) effects on inhibition of Ca signals in spines. ------- To calculate the 5 conditions for active and passive spines: 1) click the multiconditions button 2) copy the multiconditions folder cp -r multiconditions multiconditions_pas_spine 3) click the make spines active button 4) click the multiconditions button 5) copy the multiconditions folder cp -r multiconditions multiconditions_act_spine 6) run matlab program matlab/dCa_ratio.m -------