Independent source gates reduced shared-site noise ratios in eight selected worm circuit models

We tested how variable source activity changes the relative variance effect of shared release at multi-target chemical sites. We used eight public developmental worm maps and a fixed 162-neuron panel. Both models had independent binary source gates. One model shared release across targets of a site; the comparator released each contact independently given its source gate. With source and release probabilities both 0.5, the variance ratio for summed inputs was 1.029 to 1.161. With all sources active it was 2.069 to 2.368. The two adult maps gave ratios of 1.031 and 1.029 with source variation. Their release probabilities had to be at most 0.225 and 0.214 for at least 10 percent excess at source probability 0.5. Target count normalization gave adult ratios of about 1.040. An exact covariance decomposition explains the reduction: source variation adds variance to both models. It does not remove the absolute site effect. All 16 simulated variances were within 0.72 percent of exact values in 100,000 trials per map and model. Unknown release laws, abstract binary source states, positive gains, partial maps and lack of matched activity limit the result. Code, proof, aggregate evidence, figure, hashes and external retrieval instructions support reproduction. Raw external records are excluded.

C. elegans · polyadic synapses · source activity · release noise · total covariance · connectomics · sensitivity threshold