# Phase 4Z — PN feedback and input acceptance audit

Diagnostic only. No training, no new sign hypothesis, no candidate. The two branches reproduce sealed Phase4Y reference and DPM-off conditions.
Target and three ALLNs were selected from prior data; this is mechanism exploration, not heldout validation.
All source fractions are positive arrival-weight accounting, not causal percentages or voltage attribution.

## Late positive inputs to KC 82312

| condition | source idx | body_id | type | mean fraction |
|---|---:|---:|---|---:|
| DPM_fast_current_off | 30 | 10039 | VL2a_adPN | 0.170584 |
| DPM_fast_current_off | 179 | 10198 | VA7l_adPN | 0.142137 |
| DPM_fast_current_off | 368 | 10399 | PPL202 | 0.006085 |
| DPM_fast_current_off | 484 | 10522 | VL2p_adPN | 0.007661 |
| DPM_fast_current_off | 1644 | 11761 | VP1d+VP4_l2PN1 | 0.171804 |
| DPM_fast_current_off | 6065 | 16610 | VA7m_lPN | 0.071431 |
| DPM_fast_current_off | 6842 | 17484 | DC2_adPN | 0.067442 |
| DPM_fast_current_off | 133666 | 527577 | VA6_adPN | 0.362856 |
| frozen_reference | 30 | 10039 | VL2a_adPN | 0.170718 |
| frozen_reference | 179 | 10198 | VA7l_adPN | 0.141833 |
| frozen_reference | 368 | 10399 | PPL202 | 0.006249 |
| frozen_reference | 484 | 10522 | VL2p_adPN | 0.007666 |
| frozen_reference | 1644 | 11761 | VP1d+VP4_l2PN1 | 0.171787 |
| frozen_reference | 6065 | 16610 | VA7m_lPN | 0.071424 |
| frozen_reference | 6842 | 17484 | DC2_adPN | 0.067502 |
| frozen_reference | 133666 | 527577 | VA6_adPN | 0.362820 |

## Conditional single-cell replay

Other recorded arrivals and measured APL remain fixed; original force requests and refractory logic retained. This does not test whole-brain loop necessity.
| neuron_idx | condition | mode | late spike range |
|---:|---|---|---:|
| 30 | DPM_fast_current_off | base | 187–188 |
| 30 | frozen_reference | base | 187–188 |
| 179 | DPM_fast_current_off | base | 163–163 |
| 179 | frozen_reference | base | 162–164 |
| 484 | DPM_fast_current_off | base | 193–195 |
| 484 | frozen_reference | base | 193–195 |
| 1197 | DPM_fast_current_off | base | 228–228 |
| 1197 | DPM_fast_current_off | omit_ALLN | 217–218 |
| 1197 | frozen_reference | base | 228–228 |
| 1197 | frozen_reference | omit_ALLN | 217–218 |
| 1381 | DPM_fast_current_off | base | 227–228 |
| 1381 | DPM_fast_current_off | omit_ALLN | 227–228 |
| 1381 | frozen_reference | base | 227–228 |
| 1381 | frozen_reference | omit_ALLN | 227–228 |
| 1511 | DPM_fast_current_off | base | 228–228 |
| 1511 | DPM_fast_current_off | omit_ALLN | 219–221 |
| 1511 | frozen_reference | base | 228–228 |
| 1511 | frozen_reference | omit_ALLN | 219–221 |
| 1644 | DPM_fast_current_off | base | 217–218 |
| 1644 | frozen_reference | base | 217–218 |
| 6065 | DPM_fast_current_off | base | 164–165 |
| 6065 | frozen_reference | base | 164–165 |
| 6842 | DPM_fast_current_off | base | 170–171 |
| 6842 | frozen_reference | base | 170–171 |
| 82312 | DPM_fast_current_off | base | 60–61 |
| 82312 | DPM_fast_current_off | omit_ALLN | 60–61 |
| 82312 | DPM_fast_current_off | omit_ALPN | 0–0 |
| 82312 | DPM_fast_current_off | omit_DAN | 59–60 |
| 82312 | DPM_fast_current_off | omit_DPM | 60–61 |
| 82312 | DPM_fast_current_off | omit_KC | 60–61 |
| 82312 | DPM_fast_current_off | omit_edge_1646095 | 32–33 |
| 82312 | DPM_fast_current_off | omit_edge_20992891 | 0–0 |
| 82312 | DPM_fast_current_off | omit_edge_347756 | 38–39 |
| 82312 | DPM_fast_current_off | omit_edge_3560137 | 50–50 |
| 82312 | DPM_fast_current_off | omit_edge_3811419 | 50–51 |
| 82312 | DPM_fast_current_off | omit_edge_46784 | 33–34 |
| 82312 | DPM_fast_current_off | omit_edge_749243 | 59–60 |
| 82312 | frozen_reference | base | 60–61 |
| 82312 | frozen_reference | omit_ALLN | 60–61 |
| 82312 | frozen_reference | omit_ALPN | 0–0 |
| 82312 | frozen_reference | omit_DAN | 59–59 |
| 82312 | frozen_reference | omit_DPM | 60–61 |
| 82312 | frozen_reference | omit_KC | 60–61 |
| 82312 | frozen_reference | omit_edge_1646095 | 32–33 |
| 82312 | frozen_reference | omit_edge_20992891 | 0–0 |
| 82312 | frozen_reference | omit_edge_347756 | 37–39 |
| 82312 | frozen_reference | omit_edge_3560137 | 49–50 |
| 82312 | frozen_reference | omit_edge_3811419 | 50–51 |
| 82312 | frozen_reference | omit_edge_46784 | 32–33 |
| 82312 | frozen_reference | omit_edge_749243 | 58–60 |
| 133666 | DPM_fast_current_off | base | 212–214 |
| 133666 | frozen_reference | base | 212–214 |

## Input acceptance

| odor | requests | accepted reference | accepted off | status differences | first difference ms |
|---:|---:|---:|---:|---:|---:|
| 0 | 131 | 75 | 73 | 8 | 51.8 |
| 1 | 186 | 77 | 77 | 17 | 57.4 |
| 2 | 122 | 54 | 52 | 12 | 56.3 |
| 3 | 95 | 41 | 39 | 3 | 85.3 |
| 4 | 78 | 31 | 32 | 6 | 54.3 |
| 5 | 215 | 92 | 91 | 15 | 41.8 |

Identical requests do not establish matched delivered inputs. Refusal and preexisting spikes depend on endogenous state. No forcing clamp or altered refractory rule was introduced.
Ancestry edges require actual emission +18 steps <= downstream spike; greedy ranking is not a unique or sufficient causal path. Repeated neuron IDs indicate a time-supported recurrent motif, not proof it is the only sustaining loop.
Frozen LIF/APL, raw graph/counts, eligibility and masks unchanged. All detailed state/event checks are in regression/.