Using source trial flags reduced the slope between reported spine area change and calcium variance change by 55% in a linear test of 654 records from 12 mice

We tested whether growth of retained visual cortex spines marked lower calcium variance after response level was controlled. We used repeated optical area and calcium measurements from a published mouse study. The primary sample had 830 spine interval records, 22 cells, and 13 mice. Separate trial halves supplied variance estimates and response controls. Field means were removed, and mice had equal weight. With all trials, the area coefficient was 0.281, with a 95% mouse bootstrap interval of 0.127 to 0.460. In the same 654 records from 12 mice, applying the source trial flags reduced the coefficient from 0.281 to 0.127, a 55% point decrease. The paired decrease was 0.154, with an interval of 0.059 to 0.269. The flags excluded high baseline events or motion artifacts under the source rule. A reference kept each accepted-trial count and shared field flag pattern. Across 999 label arrangements, the coefficient range from the 2.5 to 97.5 percentile was 0.214 to 0.333. None was as low as the source-flag value. The source-flag coefficient itself had an interval of -0.118 to 0.329. Adding area to response controls gave an uncertain 2.5% prediction error decrease in excluded mice. An imposed optical scale change also changed the slope sign. The result links reported structure to a processed response measure and shows that the fitted variance rule depends on trial treatment. It does not establish a biological noise mechanism or an effect of growth on release reliability. The package preserves compact inputs, source hashes, code, all results, figures, and repeat instructions. A rebuild from the original data reproduced all 55 numerical result files.

dendritic spines · structure and function · calcium variability · trial selection · visual cortex · measurement calibration · reproducible analysis