With independent site loss, recorded size placement gave 7.54% less variance of retained weight fractions than size shuffles for 446 connections in one adult C. elegans map

We tested whether site size placement changes the variance of retained structural weight after independent loss of whole synapse sites. We used seven C. elegans brain maps with active-zone volumes and target fractions. The main panel had 162 embryonic neurons. Each connection had at least five sites. We calculated exact marginal moments and gave eligible source neurons equal weight. In adult map D8, 446 connections from 127 sources gave mean concentration 0.200675. This was 7.54% below the mean of 1,999 size shuffles within source and distinct target count groups. All draws gave higher values. Local size shuffles gave reductions of 6.26 to 7.19%. Recorded weights still gave 55.7% more mean fractional variance than equal site weights with the same counts. The adult median effective site count was 5.46, compared with a median count of eight. One site carried more than half the allocated volume in 25 of the 446 connections. Recorded values were below shuffle means in all seven maps, but several reference ranges included them. This exploratory study has one adult with volume data. It does not estimate physiological strength, loss rates, or biological protection. The package preserves a calculator, source hashes, code, calculated connection statistics, all reference draws, figures, and repeat instructions. Independent source calculations checked 7,451 connections. Exact state enumeration checked 396 cases. A second full run matched all seven analysis output files.

Caenorhabditis elegans · connectome · synapse size · active zone volume · site loss · effective site count · weighted variance · constrained size shuffle · reproducible research