Submitted:
07 September 2026
Posted:
08 September 2026
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Abstract
Animals possess multiple executable behavioral programs but ordinarily express only a subset at any moment. The Systema Behavorum treats such programs as latent execution architectures, permitting functional comparison across species despite divergent neural implementations. Here, six systems are assigned to Drosophila melanogaster—mating, reproductive investment, competition, navigation, reward, and defense—and the female post-mating transition is used to test the framework at identified-cell resolution. Mating transfers sex peptide, reducing activity in reproductive-tract sensory neurons and the ascending SAG pathway and thereby altering reproductive-state signaling through pC1. Two circuit observations distinguish altered access from altered capacity. After mating, courtship-song responses are attenuated in vaginal-plate-opening descending neurons (vpoDNs) while remaining intact in their upstream auditory inputs. Conversely, direct activation of oviposition descending neurons (oviDNs) is equally effective in virgin and mated females despite the strong mating dependence of spontaneous egg laying. A minimal circuit model further shows that the reported equality of activation thresholds is most consistent with subtractive removal of inhibition rather than altered intrinsic gain or straightforward divisive inhibition. Consistent with this interpretation, GABAergic oviINs inhibit the oviposition pathway, making post-mating egg laying a disinhibitory release, while GABAergic input to pC1 can close the receptivity gate. The same reproductive-state signal reconfigures feeding, locomotion, search, and aggression in different directions, supporting pC1 as a candidate coordination node rather than a uniform gain controller. Comparative evidence suggests that post-mating behavioral reallocation is more conserved than its molecular implementation. No known Drosophila modulator presently satisfies the criteria for a global permissive field. Thus, the fly supports coordinated, state-dependent gating through independently addressable channels while leaving a shared permissive variable as an experimentally testable hypothesis.
Keywords:
dynamic archetypal coordination
; GABAergic gating
; identified neurons
; pC1
; oviDN
; vpoDN
; Drosophila
; sex peptide
; disinhibition
; behavioral arbitration
; ARCH equation
; neurosteroids
; sterols
; systema behavorum
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