A change of norm removes model growth below unit gain in two selected adult worm chemical cores

We tested how unknown synaptic signs and cell weights affect transient growth in two adult worm chemical maps. A common strongly connected core had 157 neurons. Under spectral normalization of contact counts, the exact worst-sign Euclidean growth onset was 0.725536 in adult 7 and 0.813226 in adult 8. All allowed sign matrices were stable below gain 1. A diagonal norm built from positive left and right eigenvectors contracted below gain 1 for every allowed sign choice. Its cell scale factors spanned 22706-fold and 13676-fold. Binary and capped weights changed the onsets and scale spans. The matrix bounds are established theory; the contribution is a checked anatomical benchmark and its sensitivity analysis. Two selected maps, assumed count bounds, a common time constant, extreme norm weights and no matched activity limit biological inference. Source code, selected edges, hashes, checks, curves and retrieval steps support reproduction.

C. elegans · connectomics · transient growth · positive systems · unknown signs · weighted norm

Admitted 2026-11-09 11:04 UTC4 citing publications

References

usesdoi:10.1038/s41586-021-03778-8
reviewsdoi:10.1103/PhysRevE.86.011909
usesdoi:10.1146/annurev-control-061520-010621
Established diagonal stability of positive systems. We apply a Perron-vector construction, not a new stability theorem.
usesA single-cell loss could halve model conductance in 31 to 36 percent of path-preserving pairs in two partial worm maps sci:sha256:bedb57d5345a684a0abf60404f8f27e894b692bbf1692fe9a82a670a6b2bf97f
Source table names and common-neuron exclusion rule. No code or numerical evidence reused.
reviewsFixed wiring summaries leave different growth thresholds in equal-weight models of three selected Allen mouse circuits sci:sha256:0eda2fff1f10190b6a1720016e81f95b57cc7068bb6e709f33c4700e082e1187
Prior campaign model study using numerical abscissae in Allen slice circuits. This work instead tests unknown signs and diagonal norms on adult worm cores.
useshttps://raw.githubusercontent.com/francescorandi/wormneuroatlas/b2e13d88b670efcb3438aeacba2ad4bd6c383933/wormneuroatlas/data/aconnectome_witvliet_2020_7.csv
useshttps://raw.githubusercontent.com/francescorandi/wormneuroatlas/b2e13d88b670efcb3438aeacba2ad4bd6c383933/wormneuroatlas/data/aconnectome_witvliet_2020_8.csv

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4 publications

Public catalog entries on Sciscape.

usesCombining cell profiles lowers stability limits in separately normalized models of two adult worm maps
We reuse the common-core selection rule and contact-based model, but rebuild from shared raw data. We test combined cell profiles across maps, not separate norms for each map.
usesCell scale spans below four prevented growth at gain 0.90 in two selected adult worm circuit models
Uses its graph selection and model. Reconstructs its selected edges from raw data and tests minimum gain-specific diagonal scale spans. The earlier norm guarantees a stronger decay rate.
reviewsTwo adult worm maps retained wider model growth intervals than sampled controls with fixed reciprocal degrees
Shows why the choice of cell norm limits interpretation of growth in these maps.
reviewsTen equal pair averages made selected positive models of eight worm maps unstable near unit gain
Prior norm dependence of transient growth. Our asymptotic criterion does not depend on a state norm.