Different channel opening and calcium influx values gave equal outputs in the v1.0.0 striatopallidal synapse model

We tested whether a released synapse model can separate calcium channel opening from its calcium influx factor. We used version v1.0.0 of the Lee and colleagues striatopallidal model and its additional paired-pulse tables. The model uses the product of the two factors. An exact proof shows that equal products give equal complete calcium, release and current outputs for any fixed input schedule. We used 180 released paired-pulse ratio (PPR) values to make eight regional baseline and drug target pairs. Sixteen constructed fits, at 100 and 50 ms pulse intervals, matched both means within 7e-9 and avoided the source penalty for more than fourfold peak suppression. All 16 allowed equal drug outputs with reduced, fixed or 25% increased opening if influx could change. The source drug fit holds influx fixed; the latter alternatives relax that assumption. The common product symmetry leaves absolute opening unresolved even when influx stays fixed across conditions. The source function also has two inactive drug scale coordinates. Its default interval is 100 ms; the article gives 50 ms. The main result is unchanged after 50 ms fits. We supply a product interface, an exact event reduction, proof, original MIT source and workbooks, provenance, numerical results, figures and repeat instructions. These are model compatibility results. They do not establish an alternative mechanism in mice or invalidate the source anatomy and pharmacology.

synaptic transmission · structural identifiability · calcium · dopamine · striatopallidal synapses · reproducibility · short-term plasticity