Regulatory Evidence
NAM-vs-Animal Concordance Dashboard
How ConductScreen features map to OECD TG 426 developmental neurotoxicity endpoints, with published evidence for each mapping.
7
Features Mapped
3
Strong Concordances
4
Substance Classes Covered
Area / Equivalent Diameter
Effect Size
|r| = 0.52–1.00
ConductScreen
Morphology
Phase 1 — Validated
OECD TG 426
Cross-sectional area of brain regions
Sections 43–46
Organoid area reflects tissue growth capacity; ethanol-exposed rat pups show reduced cortical area (Maier et al., 1999); organoid area is reduced by ethanol (Adams et al., 2023).
Solidity
Effect Size
|r| = 0.57–0.67
ConductScreen
Morphology
Phase 1 — Validated
OECD TG 426
Tissue integrity / neuropathological assessment
Section 43
Solidity measures tissue compactness; decreased solidity indicates disintegration/loosening, analogous to tissue degeneration scored in TG 426 neuropathology.
Contrast / Texture Homogeneity
Effect Size
|r| = 0.62–0.79
ConductScreen
Morphology
Phase 1 — Validated
OECD TG 426
Cellular architecture / organization
Section 45
Texture features capture local cellular organization; increased contrast / decreased homogeneity indicates disrupted layering, analogous to disorganized cortical architecture in TG 426 histopathology.
Std Intensity / Intensity Range
Effect Size
|r| = 0.93
ConductScreen
Morphology
Phase 1 — Validated
OECD TG 426
Differentiation markers / heterogeneity
Sections 44–45
Intensity heterogeneity reflects differentiation state variation within organoid; analogous to altered marker expression patterns in developing rat brain.
Growth Velocity / Doubling Time
Effect Size
14.4x / 10.9x / 7.5x fold-change
ConductScreen
Temporal
Phase 1 — Prototype
OECD TG 426
Brain weight / body weight ratio
Sections 41–42
Organoid growth rate is the in vitro analog of brain growth; dose-dependent growth arrest (Yao 2020, methadone) parallels reduced brain weight in exposed rat pups.
Boundary Roughness / Fractal Dimension
Effect Size
Proof-of-concept
ConductScreen
Boundary
Phase 2 — Planned
OECD TG 426
Neurite outgrowth / dendritic arborization
Sections 45–46
Boundary roughness in brightfield is a proxy for neurite-producing organoids; smooth boundaries indicate compact organoids with less outgrowth. Multiple substance classes affect neurite coverage in published review literature.
Burst Rate / Synchrony Index
Effect Size
Phase 2 planned
ConductScreen
Electrophysiology
Phase 2 — Planned
OECD TG 426
Functional neuronal activity / behavioral endpoints
Sections 47–51
MEA electrophysiology in organoids measures functional network activity; substance-disrupted network formation produces altered burst patterns analogous to behavioral deficits in exposed rat pups.
Full Concordance Mapping
Tabular overview of all ConductScreen-to-TG 426 mappings
| Feature | Module | TG 426 Endpoint | Strength | Substances | Effect Size |
|---|---|---|---|---|---|
| Area / Equivalent Diameter | Morphology | Cross-sectional area of brain regions | Strong | 3/9 | |r| = 0.52–1.00 |
| Solidity | Morphology | Tissue integrity / neuropathological assessment | Strong | 3/9 | |r| = 0.57–0.67 |
| Contrast / Texture Homogeneity | Morphology | Cellular architecture / organization | Moderate | 3/9 | |r| = 0.62–0.79 |
| Std Intensity / Intensity Range | Morphology | Differentiation markers / heterogeneity | Moderate | 3/9 | |r| = 0.93 |
| Growth Velocity / Doubling Time | Temporal | Brain weight / body weight ratio | Strong | 3/9 | 14.4x / 10.9x / 7.5x fold-change |
| Boundary Roughness / Fractal Dimension | Boundary | Neurite outgrowth / dendritic arborization | Emerging | 3/9 | Proof-of-concept |
| Burst Rate / Synchrony Index | Electrophysiology | Functional neuronal activity / behavioral endpoints | Emerging | 1/9 | Phase 2 planned |