In 11 mice, spine pairs in visual cortex gave no clear extra eye-response agreement at 2–5 versus 10–20 µm after total-response control

We tested whether nearby synaptic inputs on a dendrite share relative responses to the two eyes. We used the released Jenks et al. visual-cortex data. We made a checked extract of 4,004 spine records in 13 neurons from 11 mice. We recovered fractional fluorescence units from the stored raw and corrected traces. All 8,008 eye-trace fits had maximum error below 4.8e-13 z-score units. The main test used 3,969 records in 238 fields. It compared path distances from 2 to less than 5 micrometres with 10 to less than 20 micrometres in the same field. Each pair score used different repeat halves. We removed a linear relation between eye contrast and total response. Mice had equal weight. The near minus far covariance score was 0.0282, with a 95% whole-mouse bootstrap interval from -0.0013 to 0.0677. A test with 9,999 response-label assignments within fields gave two-sided p=0.0824. The main test did not establish a local advantage. Some fixed controls gave stronger estimates. Removing source trials marked as possible back-propagating action potentials reduced the estimate to 0.0127, with an interval from -0.0154 to 0.0502. An exploratory scale audit changed the sign of 11.3% of source peak eye indices, mostly near weak eye bias. These are results for processed calcium signals. They do not identify presynaptic cells or prove a cause of local organization. The package contains compact data, figures, code, source hashes, plans and offline reproduction instructions. All eight validation checks passed. Two full analysis runs gave identical result values.

dendritic spines · ocular dominance · structure and function · calcium imaging · trial noise · data reuse