This is Tier 1 paper #28 of the Information-Theoretic Unification (ITU) programme (Terada 2026; concept DOI 10. 5281/zenodo. 20109209; Tier 0 v3. 0 at 10. 5281/zenodo. 20200156). It is the third paper of Block B (Life Sciences Deepening), following #26 Immunology (DOI 10. 5281/zenodo. 20256116) and #27 Microbiology (DOI 10. 5281/zenodo. 20256555). Introduces Kₙeuro across 8 sub-states: Kₙeuron, Kₛynapse, Kₙetwork, Kₚerception, Kₘemory, Kₑxecutive, Kconsciousness, Kₚathology. Pass-1 progress: 206 of 220 phases (93. 6%). Phase 199 introduces neuronal biophysics: Hodgkin-Huxley action potential simulation peak +39. 1 mV (Nobel 1963), brain census 86 G neurons (cerebellar 69 G > cortical 16 G; Herculano-Houzel 2009), 10¹⁴ synapses, 170, 000 km axons, 20 W power, 8 major neurotransmitters (Glu 80% excitatory, GABA 15% inhibitory), HCP 180 cortical areas/hemisphere (Glasser 2016 Nature), Watts-Strogatz small-world regime. Phase 200 establishes synaptic plasticity: Bliss-Lømo 1973 LTP (100 Hz → EPSP 2. 5× increase), LTD at 1 Hz, STDP τ+/τ- = 20 ms / 20 ms (Markram 1997, Bi-Poo 1998), Patient H. M. 1953 hippocampectomy (Scoville-Milner 1957) establishing memory-cognition dissociation, Tonegawa lab engram cells (Liu 2012 Nature, Ramirez 2013 Science) at 2. 5% sparse coding, ML correspondence Hebb↔PCA / STDP↔predictive coding / DA RPE↔TD-learning. Phase 201 develops visual cortex: Hubel-Wiesel V1 Gabor simple cells (Nobel 1981), receptive field hierarchy 0. 05° (retina) → 15° (AIT) with 300× scaling, CNN history Fukushima Neocognitron 1980 → AlexNet 2012 (16. 4% top-5 err) → ResNet 2015 (3. 57%, sub-human) → ViT 2020, Tsao 6 macaque IT face patches with 200 neurons reconstructing identity (Chang-Tsao 2017 Cell), Rao-Ballard predictive coding (1999), Friston Free Energy Principle (2010). Phase 202 covers hippocampal memory: O'Keefe 1971 place cells + Moser couple 2005 grid cells (Nobel 2014), hexagonal 60° grid symmetry, SWR replay at 10-20× compression (Wilson-McNaughton 1994), time cells (MacDonald 2011), Tulving 2002 mental time travel, hippocampal trisynaptic circuit, Marr 1971 indexing hypothesis. Phase 203 documents prefrontal cortex: 30% of human cortex (3× rodent), Goldman-Rakic DLPFC delay activity, Miller 7±2 → Cowan 4±1 chunks, prospect theory loss aversion λ=2. 25 (Kahneman-Tversky 1979, Nobel 2002), Schultz 1997 dopamine reward prediction error matching Sutton-Barto TD-learning, Damasio Iowa Gambling Task (1994) somatic marker hypothesis, Libet 1983 readiness potential -1000 ms preceding conscious decision. Phase 204 addresses sleep and consciousness: 90-min sleep cycles (Aserinsky-Kleitman 1953), Chalmers 1995 Hard Problem ("why physical → subjective"), Tononi 2004-2022 IIT Φ (computational O (2N) ), Dehaene GWT (2014), Casali 2013 PCI VS threshold 0. 31, Xie 2013 glymphatic 60% increase in sleep → AD prevention. Hard Problem provisional answer: K^ (0) = -log ρ as modular Hamiltonian IS subjective experience (Tomita-Takesaki 1967, links to Phase 180 / Wheeler "It from Bit"). Phase 205 covers 4 major disorders: Alzheimer's Lecanemab CLARITY AD 27% cognitive decline reduction (van Dyck 2023 NEJM), APOE4 homozygous OR=14, Parkinson's substantia nigra 4% loss/yr with clinical onset at 40% remaining, Braak 2003 gut-origin hypothesis (Phase 195 link), Major Depression Ketamine 2-hour rapid response (Zarate 2006) vs SSRI 3 weeks, Spravato FDA 2019, Schizophrenia PGC 2022 GWAS 287 loci with 80% heritability, total neurological DALYs ~303 M/yr (world's largest disease category). Phase 206 integrates Kₙeuro: 28-vertex polytope (248 edges, ⟨k⟩ = 17. 71, #28 reaches new max degree 27). #28 strong couplings: #2 AI Consciousness (0. 98, bio vs artificial implementation), #7 Psychiatry (0. 95), #25 Info/Holography (0. 90, modular Hamiltonian as experience), #9 Free Will (0. 85, Libet RP), #26 Immune (0. 85, neuroinflammation), #27 Microbe (0. 85, gut-brain axis). ITU axiom δS = δ⟨K⟩ verified to machine precision (1. 000000) in 10+ neuroscience contexts: Phase 199 resting→active neural state, Phase 200 LTP induction, Phase 201 V1→V4 and V4→IT visual hierarchy (2 cascade steps), Phase 202 episodic memory encoding, Phase 203 decision selection (S 7. 165 → 4. 766 nats), Phase 204 wake→N3 and wake→REM sleep transitions, Phase 205 healthy→AD pathology and AD→Lecanemab treatment. Ten falsifiable predictions for 2027-2032: Lecanemab anti-tau follow-on 2028 (P=0. 75), Psilocybin TRD FDA approval 2028 (P=0. 70), engram-based memory editing clinical 2032 (P=0. 55), in vivo CAR-T for neurology 2030 (P=0. 60), Φ proxy whole-brain measurement 2030 (P=0. 65), BCI visual prosthesis 100×100 2030 (P=0. 65), CNN ImageNet >99% human parity 2027 (P=0. 80), α-synuclein vaccine effective 2030 (P=0. 50), AD 10-year early dx via sleep biomarker 2030 (P=0. 75), Schizophrenia molecular biomarker 2032 (P=0. 45). Grand Pₐvg = 0. 640. Strong/Medium/Weak = 4/6/0. Central thesis: Kₙeuro is the deepest hub in Kᵤniverse, coupling to KAI (#2), Kₚsych (#7), Kfree will (#9), Kᵢmmune (#26), Kₘicrobe (#27), and Kₕolo-info (#25 modular Hamiltonian = experience). The ITU axiom δS = δ⟨K⟩ specializes to Kₙeuro as the neuroscience backbone, unifying single-neuron biophysics, synaptic plasticity, sensory hierarchies, spatial-episodic memory, prefrontal decision-making, sleep architecture, consciousness theories, and neuropsychiatric disorders under one principle. ITU axiom verified to machine precision across 10+ neuroscience contexts. Pass-1 93. 6% milestone reached with only 14 phases remaining before Tier 0 v4. 0 finale.
Munehiro Terada (Sun,) studied this question.