💊 SCN9A Pain Insensitivity — 3D

The 2D original walks through five stages of the SCN9A / NaV1.7 story on a flat canvas: a functional NaV1.7 sodium channel amplifies small stimuli into pain-firing action potentials, a rare loss-of-function mutation silences it, the resulting congenital pain insensitivity leaves touch and temperature completely untouched, and that clean human "knockout" becomes genetic validation for a whole class of non-opioid NaV1.7-blocker drugs. Every number on screen came from a shared formula set: pain sensation tracks NaV1.7 function level 1:1, other sensation stays pinned at 100% (dissociated from NaV1.7 entirely), and target confidence is confBase[stage] * population/3, damped further toward zero in the first two stages regardless of population size. This 3D companion keeps that exact model — the same five stages, the same default function/population pairs, the same confidence formula — and renders it as a genuine orbitable Three.js scene: a real DRG neuron soma with dendrites, nine NaV1.7 channel gates spaced along a 3D axon that individually turn from glowing teal to inert grey as the Function Level slider moves, a parallel Aβ touch/temperature fiber that keeps firing pulses no matter what NaV1.7 does, a spinal-cord/CNS gate structure that flashes when a pain pulse actually arrives, a simplified human figure whose head recolors between "Pain: Present" and "Pain: Absent", and a rotating six-atom drug-molecule ring that fades into view once target confidence crosses the same 45% threshold as the original. A new Axon Conduction Velocity slider adds one genuinely independent physiological axis: real axons vary in how fast a fired signal physically travels depending on myelination and fiber diameter, completely separate from whether NaV1.7 opens at all — so this control only rescales how fast the pain and touch pulses move down the axon, never how many channels are functional or what the pain/confidence numbers read.