With partner counts by cell type fixed, side constraints cut chemical input cosine excess by 86% at 350 putative electrical pairs in one Ciona map

We tested whether putative electrical contacts join cells with similar chemical inputs in one Ciona larva connectome. We matched 174 neuron records across published tables and kept 350 unordered electrical pairs with at least 0.12 micrometre summed contact depth. The mean chemical input cosine was 0.25987. Controls that fixed each neuron's electrical partner counts by cell type gave a mean of 0.23345. The excess was 0.02641. Adding reported soma side to those counts raised the reference mean to 0.25630 and cut the excess by 86.5%. Binary feasibility checks found that type and side constraints forced 267 of the 350 recorded pairs. Only 83 could change. For binary chemical inputs, the observed cosine of 0.36170 lay within the type and side reference range of 0.35740 to 0.36385. Chemical output profiles showed a similar pattern. Exploratory controls also fixed chemical pair status. A check found that these edge-switch chains missed ten pairs that could change under the full constraints. We therefore report those samples as references within the starting switch component. This result concerns graph constraints in one released map. It does not establish random wiring, functional coupling, or a cause of the pattern. The package gives code, numerical extracts, source hashes, feasible graph witnesses, figures, and repeat instructions.

Ciona · connectome · electrical synapses · chemical inputs · bilateral asymmetry · conditional graph models · edge switches