Bipolar threshold levers — the mood-stabiliser barrier-raise, decomposed into three DNA-grounded levers

The previous chapter's mood-stabiliser barrier-raise is decomposed into a DNA-grounded three-lever target map: reduce the inward excitatory current (L1), increase the outward potassium current (L2), or remove the upstream circadian and HPA drive (L3). Sixteen bipolar genes are placed by their own promoter switch stiffness. Targets are ranked, never drugs or doses; efficacy=0; not medical advice.

The bipolar chapter closed with a forced sign: a mood stabiliser is whatever raises the barrier between the manic and depressive poles (result B4). That is correct and direction-only, but it leaves the operator abstract — it says raise the barrier without saying which genes or channels actually realise the raise. This chapter fills exactly that gap, and it does so with a piece of technology built elsewhere and inherited wholesale: the threshold-shift intervention logic from the analgesic reproducibility package (Zenodo 10.5281/zenodo.20733420). Its core idea is that a symptom is a firing-threshold crossing and an intervention is a controlled upward shift of that threshold, reachable exactly three ways: L1 reduce the inward (excitatory) current, L2 increase the outward (potassium) current, L3 remove the up-stream sensitising drive. Applied to bipolar disorder on the same R19 substrate the whole atlas rests on, the abstract barrier-raise resolves into a three-lever target map over sixteen bipolar excitability genes: the voltage-gated Ca²⁺/Na⁺/NMDA set on L1 (with CACNA1C and ANK3, the two classic GWAS loci), the KCNQ / KCNB potassium set on L2, and the circadian / HPA set on L3 (with GSK3B, lithium's best-characterised molecular target). Each gene is placed by reading its own promoter switch stiffness — γ = −mean nearest-neighbour stacking free energy (SantaLucia 1998) over its promoter window, turned into |h_sp| = spinodal(γ) with the frozen engine read-only. Three fail-closed disciplines ride along: every L3 link stays graded [O] cited biology, a forbidden-claim scanner rejects any dose / efficacy / safety / synthesis statement, and a burden-weighted ranking orders targets, never drugs or doses. The firewall is absolute: the promoter |h_sp| is a gene's own switch stiffness, never a channel voltage, a potency, a dose, or a clinical effect. efficacy = 0; not medical advice; the hard problem stays open.

the §29 mood-stabiliser barrier-raise decomposed into a DNA-grounded three-lever target map = the abstract barrier-raising operator of B4 is resolved into three concrete levers (L1 reduce inward excitatory current, L2 increase outward K+ current, L3 remove the upstream circadian/HPA drive) over 16 bipolar excitability genes placed by their own promoter switch stiffness; targets are ranked, never drugs or doses — the bipolar chapter's B4 proved the mood-stabiliser SIGN is barrier-raising but treated the stabiliser as ONE undifferentiated operator -- it never said WHICH genes or channels realise the barrier-raise. This module inherits the threshold-shift intervention logic from the analgesic reproducibility package (Zenodo 10.5281/zenodo.20733420) and uses it to DECOMPOSE that single operator into a three-lever target map on the SAME R19 substrate, with NO new mechanism and NO new tuned constant. A symptom is a firing-threshold crossing and an intervention is a controlled UPWARD shift of that threshold, reachable three ways: (L1) reduce the inward, excitatory current -- the voltage-gated Ca2+/Na+/NMDA set CACNA1C, CACNA1D, CACNA1I, SCN2A, GRIN2A, with CACNB2 and ANK3 L1-adjacent; (L2) increase the outward, repolarising K+ current -- the KCNQ2/KCNQ3 M-current pair and KCNB1; (L3) remove the up-stream sensitising drive -- the circadian/HPA set ARNTL(BMAL1), CLOCK, PER2, NR3C1, CRHR1 and GSK3B (lithium's best-characterised molecular target). Each gene's gamma = -mean(nearest-neighbour stacking dG, SantaLucia 1998) is read from its OWN promoter window (TSS-2000..+500, Homo sapiens) and turned into that promoter's switch stiffness |h_sp| = spinodal(gamma) and barrier = gamma^2/4 using the frozen engine READ-ONLY -- the identical pipeline the analgesic package ran for the Na_V channels, and the identical R19 primitive the bipolar chapter uses. Three fail-closed disciplines ride along: an L3-honesty gate keeps every L3 mechanism link graded [O] cited biology (never derived); a forbidden-claim scanner rejects any dose, efficacy, safety or synthesis statement (with a planted self-test that must fire); and a burden-weighted prioritisation ranks TARGETS (CACNA1C and ANK3 top the genetic-burden tier, GSK3B and the circadian set follow) with the gamma read carried alongside as structural context but NEVER folded into the score. FIREWALL (non-negotiable): the promoter |h_sp| is the gene's own switch stiffness, NEVER equated with the sec.29 network mood-switch barrier g, nor with a channel's activation voltage, a drug's potency, a dose, an in-vivo selectivity, or a clinical effect. Registered in run_all_atlas.py as the 8th atlas citizen (BIP-T2b-L), reproducing bit-for-bit with engine byte-unchanged. medium_efficacy_tested=0; ranks targets not drugs; not medical advice; hard problem OPEN. [V map · O links]. this chapter

bipolar = two operating poles on ONE valence axis; episodes are bistable switches, kindling is the retained trace = mania sits above health and depression below (one axis, two excursions); an episode is a bistable transition (E2 hysteresis+latency); kindling is the E0 trace accumulating across episodes (each switch easier); the mood-stabiliser sign is barrier-raising — bipolar is the second TEMPORAL disorder and the first to USE the state-switching layer: it IMPORTS both PlasticConnectome (E0, the slow trace) and BistableSwitch (E2, the fast switch) and re-derives neither. The axis is the engine's own M17 valence geometry (dopaminergic approach pole, M18 cortisol cascade on the withdrawal pole), mapped to a sustained bias through the SAME coupling map k=κ/(1−|b|)[approach]/κ/(1+|b|)[withdrawal] cap 2κ the SZ/epilepsy/E0 modules use — no new constant; every sign holds over a severity sweep. Five results: (B1) an approach bias raises the global order parameter ABOVE health (R=0.422>0.390), a withdrawal bias lowers it BELOW (0.367<0.390), euthymia is the anchor between, ordering depressive<euthymic<manic monotone — NOT two diseases but two excursions on one axis; (B2) an episode is a bistable transition inheriting E2's hysteresis (loop 2·spinodal≈0.77) and its latency falling with overshoot (31.6→1.9), so an episode is entered at one fold and only left at the other (it persists past its trigger) and a slow approach gives a prodromal run-up; (B3) kindling = the E0 trace accumulating across alternating manic/depressive episodes (‖ΔW‖ deepening 0.06→0.11→0.17→0.22→0.27→0.33 over episode count, across an η sweep), and a deeper trace LOWERS the barrier so each subsequent switch needs less drive — history makes the next episode easier; (B4) the mood-stabiliser sign is whatever RAISES the barrier — raising the well depth raises the flip threshold (0.38→0.44→0.51→0.64) so both manic and depressive switches become harder to enter (the direct counterpart of kindling); (B5) η=0/no-bias reproduces the frozen M9 anchor R=0.38961455156044245 bit-for-bit, W identical, static==settle (engine e61083ae…, tree 0fbf4988…, byte-unchanged). Bipolar is what E2 and E0 do TOGETHER on the valence axis, no third mechanism invented. Axis-A firewall: a bistable transition and a retained trace are mechanism boundaries, not a claim about the felt quality of a mood state (consciousness_claim=0). Heterogeneity (bipolar I/II, cyclothymia, mixed states, rapid cycling, psychosis) is LOCKED. Addiction (T3a, sensitisation) is owed. efficacy=0; not medical advice; hard problem OPEN. [V mech]. canonical §29

What B4 left abstract

The previous chapter read bipolar disorder as two poles on one valence axis and proved five sign-only results. The fourth, B4, is the one this chapter builds on: the mood-stabiliser sign is barrier-raising — anything that deepens the well around euthymia raises the threshold to switch, so both manic and depressive episodes become harder to enter. That result is forced and it is honest, but it describes the stabiliser as a single abstract operator: raise the barrier. It does not say by what physical handle the barrier is raised — which current, which channel, which gene. A mechanism atlas should be able to say more than something raises the barrier; it should be able to enumerate the ways a barrier can be raised and attach real molecular targets to each. That enumeration is precisely what the inherited technology supplies.

The inherited technology: threshold-shift intervention logic

The handle is not invented here. It is taken intact from the analgesic reproducibility package (Zenodo 10.5281/zenodo.20733420), which built a threshold-shift intervention logic for a different problem (a pain-signalling threshold) and proved it on the voltage-gated sodium channels. Its premise is general: if a symptom is a firing-threshold crossing, then an intervention is a controlled upward shift of that threshold, and a threshold is set by a balance of currents, so there are exactly three levers on it. L1 — reduce the inward, excitatory current that drives the system toward the crossing. L2 — increase the outward, repolarising current that pulls it back. L3 — remove the up-stream sensitising drive that lowers the threshold in the first place. The same frame applies unchanged to the bipolar mood switch, because the bipolar chapter and the analgesic package share the same R19 substrate — the engine's supercritical pitchfork ṣ = g·s − s³ + h, whose spinodal fold IS the switching barrier. Inheriting the logic means the bipolar barrier-raise of B4 is not one operator but three named levers, and each lever points at a concrete set of genes.

The reuse is literal at the level of code, not just analogy. The analgesic package read each channel gene's promoter on a fixed pipeline and turned it into a switch stiffness through the engine's own spinodal and barrier functions; this chapter runs that identical pipeline on the bipolar genes, and two of the potassium-channel reads (KCNQ2, KCNQ3) are carried over verbatim from the analgesic cache — the same gene, the same number. Nothing about the engine is touched; the module re-emerges the frozen tree read-only and confirms it byte-unchanged.

L1 — reduce the inward excitatory current

The first lever lowers the drive toward the switch. In bipolar genetics this is the richest lever, because the disorder's most-replicated common-variant signals sit on voltage-gated calcium channels. CACNA1C (Ca_V1.2) is the single most-replicated bipolar GWAS locus; CACNA1D (Ca_V1.3) and CACNA1I (Ca_V3.3) extend the calcium-channel signal across the cross-disorder analyses; SCN2A (Na_V1.2) carries the voltage-gated sodium side and GRIN2A the NMDA-receptor (glutamatergic, calcium-permeable) side. Two more sit L1-adjacent: CACNB2, the auxiliary calcium-channel β2 subunit that is itself a cross-disorder GWAS hit, and ANK3 (ankyrin-G), the second classic bipolar locus, which organises the sodium channels at the axon initial segment rather than carrying current itself. The mechanism DIRECTION on this lever is the one the existing mood stabilisers already illustrate: agents that reduce voltage-gated inward current (the sodium-channel-blocking anticonvulsant stabilisers are the textbook example) are barrier-raising in the L1 sense. That is a direction, never a dose — efficacy = 0.

L2 — increase the outward potassium current

The second lever raises the pull back from the switch by strengthening the outward, repolarising potassium current. Three channels carry it here: KCNQ2 and KCNQ3 (K_V7.2 / K_V7.3, the neuronal M-current pair that is the canonical excitability brake), and KCNB1 (K_V2.1, the major somatic delayed-rectifier). On the inherited frame, an M-current opener — anything that increases this outward current — is barrier-raising in the L2 sense, the mirror image of the L1 inward-current reduction. The two KCNQ reads are the genes carried over verbatim from the analgesic package's potassium set, which is what makes the L1/L2 symmetry exact rather than approximate: the same channels that brake a pain-signalling threshold brake the mood switch, read on the same pipeline. Again the claim is a mechanism direction only; no opener, dose, or patient is named.

L3 — remove the upstream circadian / HPA drive (the [O] lever)

The third lever does not touch the channel at all; it removes the up-stream drive that keeps the threshold low. In bipolar disorder this drive is the one the disorder is most characteristically tied to: the circadian clock and the HPA stress axis. The clock genes ARNTL (BMAL1), CLOCK and PER2 sit here — the Clock-Δ19 mouse shows a mania-like phenotype, and lithium lengthens circadian period — alongside the HPA effectors NR3C1 (the glucocorticoid receptor) and CRHR1 (CRF-receptor-1, at the top of the axis). And the lever's anchor gene is GSK3B: GSK-3β is lithium's best-characterised molecular target, sitting where the circadian and mood-stabilising actions converge. This is the lever that demands the most discipline, and it gets it. Every L3 link is held at grade [O] — open, cited biology, never derived from the substrate. The model does not claim to compute that GSK-3β or BMAL1 sets the bipolar threshold; it records, as cited upstream biology, that these are the drives whose removal would raise it. A fail-closed L3-honesty gate enforces exactly this: it checks that the declared L3 set is present, that each member is graded [O] and marked not-derived, that no L3 gene is mislabelled as a current-carrying ion channel, and that the firewall sentence is present — and it FAILS the build if any of these slips.

The DNA grounding: a promoter's own switch stiffness

What places each of the sixteen genes is not a list but a read. For every gene, the module takes its promoter window (transcription start −2000 to +500 bases, Homo sapiens) and computes γ = −mean of the nearest-neighbour base-stacking free energies along that window (the SantaLucia 1998 nearest-neighbour thermodynamics), then turns that γ into the promoter's switch stiffness through the frozen engine's own functions: |h_sp| = spinodal(γ) = 2(γ/3)^1.5 and barrier = γ²/4. The reads span a real range — from KCNQ2 at γ ≈ 1.58 (|h_sp| ≈ 0.76, the stiffest promoter in the set) down to SCN2A at γ ≈ 1.20 (|h_sp| ≈ 0.50) — and they are read on the same R19 substrate, with the same engine, that the analgesic package used, which is the whole point of the inheritance: one substrate, one pipeline, two problems. The γ read is a property of the gene's promoter sequence, and that is all it is.

Ranking targets, and the firewall that keeps gamma honest

The last component prioritises, and it prioritises targets, never drugs or doses. A burden-weighted score combines three declared, cited weights — clinical burden, unmet need, and genetic-evidence / druggability — and ranks the genes by that score alone. CACNA1C and ANK3 top the list (the two highest-burden bipolar loci), GSK3B and the circadian / HPA set follow. Crucially, the γ read is carried alongside each target as structural context but is never folded into the score — and the result is a clean demonstration of the firewall: the priority ranking and the γ / |h_sp| ranking are decoupled. CACNA1C is the top-priority target yet has nearly the softest promoter read in the set; KCNQ2 has the stiffest read yet sits low on priority. If the stiffness drove the ranking, those two could not sit where they do. That decoupling is the firewall made visible, and it must be stated once more in full: the promoter |h_sp| is a gene's own switch stiffness, and it is never equated with the network mood-switch barrier g of the previous chapter, nor with a channel's activation voltage, a compound's potency, a dose, an in-vivo selectivity, or any clinical effect. A fail-closed forbidden-claim scanner guards the whole package: it scans the written results for any dose, efficacy-as-fact, safety-as-fact, or synthesis statement, carries a negation guard, and includes a planted self-test that must fire — if it ever fails to catch its own bait, the build fails. This module is registered as the eighth atlas citizen (BIP-T2b-L) and reproduces bit-for-bit with the engine byte-unchanged.

Everything here is an in-silico reading of promoter sequence and a frame for organising targets, not a clinical measure, a diagnosis, or a prescription. The model asserts mechanism directions and target placements — a barrier can be raised three ways; these sixteen genes populate the three levers; these targets carry the highest genetic burden — and nothing about which agent acts on any lever, at what dose, in whom, whether any real drug raises anyone's barrier, or that anyone should change a treatment. The mood stabilisers named as directions (the sodium-channel-blocking anticonvulsants on L1, lithium via GSK-3β / circadian on L3) are illustrations of a sign, never a recommendation. Real bipolar disorder is heterogeneous and polygenic, and that heterogeneity is locked. A promoter read and a lever assignment are mechanism boundaries, not a claim about the felt quality of a mood state (Axis-A firewall — consciousness_claim = 0, the hard problem stays open). This is not medical advice, not a diagnosis, not a treatment protocol, and not a cure. medium_efficacy_tested = 0; targets ranked, never drugs or doses.