Morphometric model of normal rabbit dorsal root ganglia.

Abstract

The rabbit dorsal root ganglion is an important model of pain mechanisms in the human spine. A morphometric model of the normal rabbit dorsal root ganglion was constructed to provide quantitative comparisons with injured ganglia. Lumbar ganglia were studied under light and electron microscopy using simple stereologic methods. Neuronal diameter ranged from 18 to 85 microns, with 60% between 30 and 50 microns. Neurons constituted approximately 30% of dorsal root ganglion volume, and neuronal nuclei accounted for 14% of neuronal volume and 4% of dorsal root ganglion volume. Contributions from organelles to dorsal root ganglion volume were: mitochondria, 1.5%; rough endoplasmic reticulum, 9.4%; lysosomes, 0.2%; golgi, 0.5%. This morphometric model facilitates quantitative analysis of ganglia exposed to direct or indirect stimuli, providing important information on the structural changes that influence pain production.