Keeping two-way pairs reversed induced cycle count comparisons under local partner controls in one FlyWire v783 central graph at five synapses per edge

We tested three-neuron cycles in one adult female fly brain. The graph had 32,383 central neurons and 849,928 directed connections with at least five synapses. An induced cycle had three ring edges and no reverse edge. We counted cycles with only acetylcholine or GABA labels. The graph had 56,085 induced cycles. References kept each neuron's partner counts by transmitter, soma side and main connection region. Without fixed two-way pairs, the mean count was 94,495. With every two-way pair fixed, it was 40,722. The measured count changed from below to above the central 95% sampled ranges. With two-way pairs fixed, its count ratio was 1.38 at five synapses and 1.39 at ten. The primary share of cycles with one GABA neuron was 54.91%, within the five-synapse range of 54.85 to 56.20%. At ten synapses, this share was 58.47%, above the range of 56.27 to 58.25%. Each reference used two seeds and 120 saved graphs. Independent code checked counts and fixed margins. These finite switch samples are not a proved uniform sample of all allowed graphs. One brain and structural labels cannot establish physiological feedback. The package gives code, source hashes, traces, checks, figures and repeat instructions.

connectome · FlyWire · directed cycles · neurotransmitter · reciprocity · constrained graph reference