Anatomy & pathways / Computational laboratory

Peripheral Nerve Regeneration

Follow individual axons through degeneration, repair, distal advance and remyelination. Change the assumptions. Inspect the consequences.

Exploratory mechanistic model

Literature-informed mechanisms with explicit, adjustable assumptions. Synthetic anatomy. Outcomes describe this model; human recovery and treatment efficacy are not calibrated.

Start with an example

01 / Experimental conditions

Injury & repair geometry

Biological context

Context labels preserve species provenance. Every parameter remains explicit; this is not a species-calibrated predictor.

Injury Repair architecture

Gap mmDistal path mm

Distal path is measured from the distal stump to the target, in addition to the gap.

Repair delay daysNerve radius mm

Time horizon

Growth & tissue assumptions

Unimpeded elongationPotential arc-length advance before local environmental resistance.Growth initiation lagA separate heterogeneous clock after the pathway becomes available.Track alignmentGuidance and synthetic fascicle geometry; not surgical skill.Repair-state supportAmplitude of normalized Schwann repair-state availability.Vascular supportPermissiveness index, not blood flow or oxygen concentration.Scar burdenAdjustable obstruction hypothesis; no collagen mechanics.Distal support half-lifeAssumed persistence of the denervated repair environment.Neuronal competence half-lifeInitiation competence after chronic axotomy; not neuronal death.Target receptivity half-lifeIndependent diagnostic. Does not gate or rescue growing axons.Local myelination lagDelay measured from the arrival of each axon at each location.Myelin maturation time constantExponential maturation hypothesis; not measured sheath thickness.Motor identity fractionDescriptive fiber identities; target-specific recognition is absent.

Sampling & reproducibility

Representative parent axonsRandom seedMaximum integration step

The same seed reproduces the same cohort. Numerical parents are not a measured count of all axons in a real nerve. Large cohorts retain every trajectory in analysis.

Preparing experiment…

02 / Injury windowAxons across the repair site

DAY 0

Preparing anatomical view…

Proximal stump8 mm gapDistal stump → target

Anatomy layers & display scale

Cutaway sheath Repair Schwann cells Vascular guides Distal debris Scar

Procedural anatomy · transverse scale ×3 · fiber diameter ×3

Day 0 / 180

Time is measured from injury. Playback speed changes only the display.

Crossed into distal stump—Unique parent axons

Reached target distance—Anatomical arrival

Fascicle-matched arrival—Original synthetic fascicle

Leading growth front—90th percentile / mm

Individual parent axonSelect trajectory

Click a fiber in the anatomical view or select an axon to inspect its state and arrival events.

03 / Full regeneration path

From the injury to the target

The anatomical view resolves the injury window. This plot includes the full distal distance; each mark is one parent axon. Marks can overlap.

04 / Structural outcomes

Crossing is only one milestone

Distal entryTarget arrivalFascicle match

All fractions use the original parent cohort. A fascicle match does not establish appropriate organ reinnervation or useful function. Dashed lines show a pinned reference.

05 / Tissue environment

Support changes along the path

DebrisRepair supportVascular supportScar

Dimensionless states, 0–1. Spatial profiles are simulated support fields, not measured cell densities or molecular concentrations.

06 / Maturation

Rebuilding the myelin sheath

Entry-site myelinConduction surrogateTarget receptivity

Myelin is averaged at distal entry among entered parents. Conduction is a dimensionless surrogate, not velocity, CMAP or strength. Target receptivity is an independent diagnostic; it does not gate growth.

07 / Stochastic variability

Repeat the same experiment

The central 80% band shows stochastic cohort variation at fixed assumptions, not biological confidence.

08 / Parameter sensitivity

Change one assumption at a time

Parameter

Distal entryTarget arrivalFascicle match

Five values, the same seed and observation horizon. A controlled sensitivity experiment within the model.

Numerical sweep values

Run a sweep to inspect numerical values.

09 / Compare hypotheses

Keep a reference experiment

Pin a completed run, change an assumption, then recompute. Endpoints and dashed curves retain the reference.

Exact numerical values at the displayed day

Readout	Value	Interpretation

Reproducible experiment

Model 1.0.1 · synthetic anatomy · local computation

How to read this model

A coupled biological sequence

An axon can cross the repair yet enter a different synthetic fascicle; reach the target coordinate while target receptivity has declined; or arrive before its sheath has matured. The laboratory keeps those events visible separately.

Use crush to inspect preserved guidance, conduit examples to explore an initially unsupported gap, and delayed repair to examine separate biological clocks. Each preset is an experiment in assumptions, not a clinical comparison of procedures.

Evidence & limits

Inspect the model behind the picture

The methods explain primary studies, species, equations, units and numerical checks. Molecular networks, collateral sprouting, detailed motor units, immune subtypes, target-specific synapses and patient anatomy are not resolved.

Read the complete model & primary-source evidence →