Matched Allen mouse slice pairs give uncertain chemical enrichment when both electrical calls must agree

We tested whether electrical coupling marks chemical connectivity in Allen r2.1 mouse visual cortex slice data. We matched inhibitory cell pairs within recording, Cre and layer labels, and 50 micrometre distance bins. The primary electrical rule required known, agreeing calls in both directions. Only 45 of 151 eligible coupled pairs had controls, in 43 recordings from 41 inferred animals. The matched difference for any chemical connection was 9.1 percentage points, with a 95% animal-cluster bootstrap interval of -9.3 to 25.6. A rule that accepted a positive electrical call in either direction retained 62 matched coupled pairs and gave 20.7 points, with an interval of 5.2 to 35.2. This rule also changed the sample. The secondary reciprocal-chemical result was sensitive to distance selection. The primary result does not resolve enrichment or show equal connectivity. Call rules, low comparison support, uncertain animal labels, and shared detection effects limit interpretation. Code, cohort IDs, matching strata, uncertainty draws, and provenance are supplied. No transfer across species or behavior is established.

electrical coupling · chemical connectivity · Allen Institute · matched comparison · inhibitory circuits · null result