Sensory input fraction and median calcium skew had a rank correlation of -0.52 across 11 fly wing muscles

We tested whether direct sensory input fraction predicts the shape of muscle calcium activity during fly flight. We joined released data for 11 matched wing steering muscles. The anatomy came from three fly connectomes, with both sides averaged within each animal. The activity data came from 74 flight records with 16.9 hours of retained activity. The response was the median skew of calcium signals after drift removal. Skew measures the asymmetry of signal changes. The rank correlation was -0.518. An exact test of all 39,916,800 muscle label assignments gave a two-sided p value of 0.107. The sign was negative in 73 of 74 records. Each connectome also gave a negative value, from -0.509 to -0.591. A record bootstrap gave a conditional 95% interval from -0.518 to -0.436. This interval keeps the 11 muscles fixed. It does not test new muscle types. A test within mechanical groups gave p = 0.113. Removing any one muscle kept a negative sign. A separate FANC table gave -0.609 and exact p = 0.052. These data show a repeated negative pattern in this set. They do not establish a general rule for muscle types. They do not show that sensory synapse counts cause sustained firing. The package provides a small benchmark, count audits, exact test code, figures, and source hashes. We reused released calcium features; we did not reprocess the original calcium traces.

Drosophila · connectome · wing steering · sensory feedback · muscle calcium · skewness · exact permutation test · MANC · BANC · Male CNS · FANC · structure and function · reproducible benchmark