Noci-Spatial: A 3D Transcriptomic Atlas of the Dorsal Root Ganglion

Summary

Noci-Spatial is a high-performance WebGL platform that bridges the gap between transcriptomic data and topographical anatomy by rendering a 3D volumetric model of the Dorsal Root Ganglion (DRG). Utilizing Three.js and a probabilistic spatial scaffold, the tool visualizes the spatial distribution of key nociceptive markers (e.g., Nav1.7, TRPV1, ATF3) across 3,000 single cells, revealing critical zonal segmentation patterns. Through its interactive "Virtual Scalpel" and neon-illuminated spinal connectome, researchers can dynamically explore single-cell phenotyping, fiber type, and excitability scores in both healthy and neuropathic states.

Abstract

Traditional transcriptomics provide a list of genes (“what”), but fail to provide spatial context (“where”). Noci-Spatial bridges this gap by rendering a 3D volumetric model of the Dorsal Root Ganglion (DRG). Utilizing WebGL for high-performance rendering, this tool allows researchers to visualize the topographical distribution of key nociceptive markers (e.g., Nav1.7, TRPV1) across the tissue architecture, revealing zonal segmentation patterns lost in standard single-cell sequencing.

Noci-Spatial SYSTEMS

Loading Atlas Data...

Target Gene

Virtual Scalpel

Single Cell Phenotyping

Hover to Phenotype

Mapped Neurons

Spinal Cord Connectome

Afferent termination in Dorsal Horn (L4)

Lamina I (Marginal)

Lamina II (Gelatinosa)

Lamina III-V (Nucleus Proprius)

Source for spinal cord image: Medcell

1. Introduction

The spatial organization of the DRG is non-random. Large-diameter proprioceptors and small-diameter nociceptors often occupy distinct “zones” within the ganglion. Understanding this topography is critical for:

Targeted Drug Delivery: Determining if therapeutic targets are accessible on the ganglion surface or buried deep within the core.
Injury Modeling: Visualizing how nerve injury (axotomy) induces spatial clusters of ATF3+ stress markers.

2. Methodology

This model was generated using a Probabilistic Spatial Scaffold:

Topology: The bilobed “peanut” shape of the L4/L5 DRG was mathematically modeled using merging spherical coordinates.
Gene Mapping: 3,000 single cells were mapped to this volume. Expression levels for specific genes were assigned based on radial distance algorithms (simulating the peripheral-central gradients observed in in vivo hybridization studies).

3. Tech Stack

Rendering Engine: Three.js (WebGL) for GPU-accelerated particle systems.
Framework: Svelte for reactive UI state management.
Data Structure: Lightweight JSON point-clouds allowing for instantaneous loading without heavy server-side processing.

4. How to Use

Rotate: Click and drag on the black canvas to rotate the DRG in 3D space.
Zoom: Scroll to zoom in on specific cell clusters.
Select Markers: Use the panel on the left to toggle between different gene expression heatmaps:
- Nav1.7: Shows broad distribution in nociceptors.
- TRPV1: Highlights heat-sensitive sub-populations.
- ATF3: Reveals localized injury clusters.