the courtship room

He sang, she heard, she answered. Drive his command group and the whole chain lights up: his song rises and so does her answer. Part one put her FlyWire FAFB v783 brain and his FlyEM male CNS brain from FLYBRAIN in the same room. The inputs are chosen and their actions emerge from the running brains. The controls and predictions were written down before the runs. This is the record, and the starting point for part two.

this is not an animation. it is the trial itself, played back from its own record: two real fly brains, his with 165,122 neurons and hers with 139,255, stepping in real time in one room. every position and every turn, his wing lifting on his own song command, her glow rising on her yes-neuron, and the sound you hear, his song exactly as her ear received it, are the experiment's numbers, frame by frame, rendered from the log in Blender. nothing was posed. seed 6 first; then the same seed with the sound cut, so you can watch what silence does to her.

he decides

His P1 cells are read every window as a courtship command group. We chose to send her scent through Or47b neurons and nearby contact cells. Driving his command group from above raised his song and her answer.

In part three, v9 cooled him at three chosen doses: his song did not become dependent on his command cells, and removing her scent and contact drive raised his command on every seed at every dose. The step did not hold as tested; v11 traced the suppression to the Or47b scent cue, while contact removal stayed open.

he sings

His pIP10, the descending song command neuron, is read as song and rendered as a real waveform. His pulse and sine wing motor neurons determine the mix. A control jitters the rhythm with the same energy; another silences P1. Together they let us ask what the rhythm and his command group contribute to her answer.

she hears

The waveform reaches her Johnston's organ through the same frequency bands the music room uses. We chose the bands and the slices; the receiving cells come from her map. Her brain runs the full step. Song reaches her through this ear, and her response rises over silence.

she answers

Her pC1 and vpoDN cells are read; vpoDN is the “yes” descending neuron. Her oviDN cells are read as the sign of a no. We chose virgin and mated states by driving or silencing sex-peptide sensory cells. With the waveform ear, song brought her answer across the chosen acceptance threshold in most seeds; silence left it below.

The wire carrying her state was already in her own FlyWire map: her SAG cells have outputs, but a serotonin transmitter prediction silenced them in a graph builder that keeps only acetylcholine, GABA and glutamate edges. BANC, a second female's brain and nerve cord map, showed the same route to pC1 in the same order and made us look again. In part two we turned her own synapses back on with a chosen positive sign.

he adapts

We chose a starting position inside his field of view so her silhouette reaches his eye. His LC10a cells are the visual class that tracks a female.

In part three, v10 drove his LC10a from her measured position: his mean song rose and the pair came closer than with the drive off. It did not establish that his next note followed what he saw; this step did not hold as tested.

Ten-seed run across six conditions: her solid arena paths, his dashed paths, and her vpoDN activity below.
ten seeds, six conditions, twenty seconds each. her path solid, his dashed; her vpoDN below.

what held, and what is open

In part one, song over silence raised her vpoDN and her pC1. Driving his command group raised his song and her answer, with her vpoDN up +98.5 Hz over ordinary song. Those links held. Rhythm remains open: her ear now hears a waveform, and the brains run near ceiling so small signals get lost. Approach is open because there is no heading readout yet. Silencing P1 and testing scent and sight remain open because the loop is noisy at this excitation. A mated no remained open with the state route excluded by the builder; the hand-closed pC1 gate also left that question open. Part two tests her restored route below.

predictionoutcome
P1 · her vpoDN, song over silenceheld
P2 · her pC1, song over silenceheld
P3 · her answer, rhythm over jitteropen
P4 · closer with song than silenceopen
P5 · his pIP10 and song fall with P1 silencedopen
P6 · her answer falls with P1 silencedopen
P8 · his P1 rises with her scentopen
P9 · her answer falls when matedopen
P11 · his LC10a rises with sightopen
P13 · driving P1 raises his pIP10 and songheld
P14 · driving P1 raises her answerheld
P9' · her answer falls with the pC1 gate closed by handopen
P17 · v7: she can say noheld
P18 · v7: she still hearsopen
P19 · v7: the state reaches her receptivity cellsheld
P17 · v8: she can say noheld
P18 · v8: she still hearsopen
P19 · v8: the state reaches her receptivity cellsheld
P21 · v9: command carries song, scale 0.9open
P21 · v9: command carries song, scale 0.8open
P21 · v9: command carries song, scale 0.7open
P22 · v9: scent raises his commandreversed at every scale; open
P25 · v10: the LC10a drive landsheld
P26 · v10: his next note follows the cueopen, both channels
P27 · v10: he turns toward heropen
P29 · v11: removing Or47b scent raises P1held
P30 · v11: removing contact raises P1open
P31 · v11: removing Or47b scent raises songheld, command and delivered sound
P31 · v11: removing contact raises songopen
P33 · v12: pIP10 and RMS, song over mute, scale 0.9open
P34 · v12: P1, song over noscent, scale 0.9open, negative mean
P33 · v12: pIP10 and RMS, song over mute, scale 0.8open
P34 · v12: P1, song over noscent, scale 0.8reversed; open
P36 · v13: LC10a, song over blindopen
P37 · v13: pIP10 and RMS, song over muteopen
P38 · v13: P1, song over noscent_ornopen
P39 · v13: next note follows LC10a over shifted controlopen, both channels
P41 · v14: total rate, 200 over 20 Hz dosereversed; open
P42 · v14: pIP10 and RMS, song over mute, 200 Hz doseopen
P43 · v14: P1, song over noscent_orn, 200 Hz doseopen
P42 · v14: pIP10 and RMS, song over mute, 50 Hz doseopen
P43 · v14: P1, song over noscent_orn, 50 Hz doseopen
P42 · v14: pIP10 and RMS, song over mute, 20 Hz doseopen
P43 · v14: P1, song over noscent_orn, 20 Hz doseopen

In part one, with song, her answer met the chosen acceptance rule in 90% of seeds. Silence brought no seeds across the threshold.

Driving his command group raised his pIP10, delivered song and her vpoDN in every seed.

Closing her gate by hand left 90% of seeds meeting the acceptance rule. A no remained open in that run.

the full record (pull request to FLYBRAIN): build/courtship_report.md holds the first comparisons; build/courtship_addendum_report.md holds the command drive and the hand-closed gate.

part two: she can say no

Protocol v8 restores her own SAG synapses with a positive sign chosen from the functional evidence of Feng and colleagues. Her state enters at both SAG types: on for virgin, off for mated. Her positive weights are scaled by 0.7, chosen before data from the v7 ladder. The same four conditions and predictions run across ten seeds. He runs raw and unchanged.

The first run, v7, used a BANC graft: P17 +61.8 Hz held, P18 -0.4 Hz stayed open, and P19 +34.3 Hz held.

SE is the standard error across seeds. Meeting the chosen accept rule is counted separately from the mean rate.

conditionaccept
virgin song10/10
mated song4/10
virgin silence10/10
mated silence0/10

Mean rates (vpoDN / pC1, Hz): virgin song 74.0 / 38.7; mated song 0.2 / 0.0; virgin silence 74.3 / 38.8; mated silence 0 / 0.

In this map her state opens the gate on its own; once she is willing, the song is not needed for her yes. No scale or tonic rate tested in the two calibration ladders printed in the v7 protocol made her yes require both the song and her state. The v8 calibration also left her answering in silence at the chosen scale, so P18 remains open.

record: v8 and v7 reports in the repository

part three: he decides, he adapts

These two steps did not hold as tested.

v9: cool him. At scales 0.9, 0.8 and 0.7, P21 stayed open: song minus P1-muted pIP10 means were +1.17 (SE 1.75), +1.28 (SE 0.65) and +0.42 Hz (SE 0.46). Delivered sound RMS differences were +0.00225 (SE 0.00304), +0.00424 (SE 0.00199) and +0.00213 (SE 0.00193), in the same order. P21 needs both measures at the same scale; none passed. P22 reversed at every scale: song minus no scent or contact gave P1 differences of -6.32 (SE 1.23), -2.32 (SE 0.24) and -1.99 Hz (SE 0.13). Removing those drives raised his command on every seed.

v11: which cue. At the chosen scale 0.9, removing Or47b scent raised P1 by +6.78 Hz (SE 1.31): P29 held. Removing contact changed P1 by +0.11 Hz (SE 0.33): P30 stayed open. P31 held for scent removal, with pIP10 +15.99 Hz (SE 6.99) and delivered RMS +0.01354 (SE 0.00647). It stayed open for contact removal: pIP10 +0.485 Hz (SE 1.264), RMS -0.00040 (SE 0.00128). These are removal minus both cues on.

v10: drive what he sees. At the chosen scale 0.9, her measured bearing and size drove LC10a directly. P25 held: LC10a rose +14.30 Hz (SE 2.42) over drive off. Mean song rose and mean distance fell in the descriptive record. P26 stayed open against shuffled drive: the difference in correlation with the previous cue was +0.0062 (SE 0.0339) for amplitude and -0.0105 (SE 0.0420) for mode. P27 stayed open: the fraction of turns toward her changed -0.0085 (SE 0.0081) against drive off. The drive landed; following the cue did not hold.

four more levers, same answer

v12: functional signs. Making vAB3 excitatory and restoring 23 silenced mAL cells as inhibitory left P33 open at scales 0.9 and 0.8 across ten seeds of song, mute and noscent. P34, P1 in song minus noscent, was negative at 0.9 (-1.45 Hz, SE 1.03) and reversed at 0.8 (-2.07 Hz, SE 0.35).

v13: a contrast eye. Uniform grey gives no visual drive; at scale 0.9, song, mute, noscent_orn and blind left P36 unsupported (LC10a, song minus blind: -0.01 Hz, SE 0.01), with P37, P38 and P39 also open. His total rate stayed near 42 Hz per neuron with her scent and 22.7 Hz without it.

v14: less scent. With the contrast eye at scale 0.9, song, mute and noscent_orn at 200, 50 and 20 Hz left P42 and P43 open at every dose; P41 reversed (song total rate, 200 minus 20: -1.23 Hz per neuron, SE 0.47). Even 20 Hz ignites him: the fraction of windows above the chosen ignition threshold in song was about 0.96–1.0 across doses, versus 0.5 without Or47b scent.

A second adult male brain-and-nerve-cord map is missing. MaleCNS v1.0 is the newest available map; MANC contains only the nerve cord.

what this means, after the levers

Across these records, the tested olfactory input at every tested dose drives this male model into a high-rate state across the network. His command cells do not control his song as tested. Cooling, a sign correction, a contrast eye and a lower dose do not change that verdict. The records point back to the model's own dynamics: thresholds, refractory period and weight scale, alongside the synthesis choices. Calibrating these is model-level work larger than a protocol. He decides and he adapts stay open until then.

Three steps hold, with a no: he sings, she hears, she answers. Two do not, as tested: he decides, he adapts. That count combines the earlier records with these tests; an open result does not mean an effect is exactly zero.

Next questions: calibrating the model; her nerve cord; more than one male; a third brain, the mosaic. The narrow sign rule, contrast eye and scent dose have been tested above. A second adult male brain-and-nerve-cord map is still missing.

how to read this

the words on this page are ours, the numbers are theirs.

what comes next

these are open questions. the model work is larger than a protocol.