In a test between two adult C. elegans maps, shared sites gave no clear extra target connection score after contact and neuron controls

We tested whether neurons that receive input at one chemical synapse site have more chemical connections to each other in a separate animal. We used site groups in adult map 7 and target connections and membrane contact in adult map 8 of C. elegans. Each map had 180 identified brain neurons. The local random model kept every site size, every source-to-target count, and target counts inside each source and 2 micrometre cube. There were 3,650 target pair events. Without outcome adjustment, the excess of connected target pairs was 39.89 per 1,000 events. After a fixed logistic adjustment for target contact area, broad neuron roles, and additive neuron terms, the excess score was 0.44 per 1,000 events. The centered random 95% range was -4.49 to 4.30. The upper-tail Monte Carlo value was 0.418. Spatial and site record checks kept the result within their random ranges. None of the six larval checks passed Holm correction. A later contact-area-only check gave an excess of 2.95 per 1,000 events. The result applies to the tested conditional models and does not establish no population effect. We provide a weighted fixed-count sampler, all draws, source hashes, figures, an exact small-matrix audit, and instructions for a full rebuild.

connectome · Caenorhabditis elegans · polyadic synapse · membrane contact · conditional randomization · cross-animal anatomy