Digital Morphometric Characterization of Lumbar Dorsal Root Ganglion Neurons in Rats

Abstract

Because of contrasting morphometric reports about dorsal root ganglion (DRG) neurons in rats, the aim of this study was to precisely characterizate these cells by means of digital imaging processing (DIP) to establish the different cellular groups located in lumbar DRG and possible correlations between different cellular morphometric parameters. DRG were extirpated from 10 male Sprague-Dawley rats, fixed, and histologically processed. Digital photomicrographs were obtained for cytomorphometric analysis of cellular diameter, cytoplasmic density, and distance to the DRG capsule. A total of 266 DRG neurons were sampled: 60% of cells presented diameters between 25 and 55μm; 64% were dark and 14.6% clear. No correlation was found between cellular diameter and cytoplasmic density. Nuclear density showed a bimodal distribution with a high correlation to cytoplasmic density. The current study demonstrates that DRG neurons in rat consist of one predominant group of cells with a mean diameter of 30 μm; these cells may exhibit a dark or clear cytoplasm with nuclear density directly related to cytoplasm density. (The J Histotechnol 33(3):113–118, 2010)

Submitted January 11 , 2009; accepted July 20, 2010.

Keywords:

• digital imaging processing
• dorsal root ganglion
• morphometric characterization
• primary afferents
• sensory neurons