With measured membrane times and nonnegative input, a passive one-compartment model needed over 5% changes in 73 of 242 mouse V1 fits within recorded windows

We tested if measured cell times can set passive models of excitatory connections. We used Allen Synaptic Physiology r2.1 recordings from mouse primary visual cortex (V1). The model had one passive compartment, a fixed measured target membrane time, and nonnegative input. A time-pair rule gave the smallest uniform change that each fitted voltage response needed on a time grid. Within recorded windows of 7.6 to 18.25 ms, 73 of 242 fits needed changes greater than 5% of fitted peak. A mouse-group bootstrap gave a fraction range of 24.1% to 36.4%. These windows were checked after a planned 20 ms test gave 81 of 242. That planned test extended all fits beyond their recorded ends. At fixed fit-derived time pairs, 63 of the 73 stored mean traces kept a bound above 5%. Only 18 also exceeded three baseline-noise standard deviations. With an added allowance of 5% plus three noise standard deviations, 11 remained. These allowances are not confidence tests. A separate linear program checked the bound. The package contains source code, provenance, selection records, certificates, figures, and repeat instructions. The result shows a mismatch between selected cell and connection measurements under the stated model. It does not establish a failure of passive dendrites or identify an active mechanism.

synaptic response · membrane time constant · passive model · model compatibility · nonnegative input · voltage deconvolution · functional connectivity · reproducible research