Sigma-1 receptor expression in sensory neurons and the effect of painful peripheral nerve injury

Background: The sigma-1 receptor (sigma1R), an endoplasmic reticulum chaperone protein, is widely distributed and regulates numerous intracellular processes in neurons. Nerve injury alters the structure and function of axotomized dorsal root ganglion (DRG) neurons, contributing to the development of pain. The sigma1R is enriched in the spinal cord and modulates pain after peripheral nerve injury. However, sigma1R expression in the DRG has not been studied. We therefore characterized sigma1R expression in DRGs at baseline and following spinal nerve ligation (SNL) in rats. Results: Immunohistochemical (IHC) studies in DRG sections show sigma1R in both neuronal somata and satellite glial cells. The punctate distribution of sigma1R in the neuronal cytoplasm suggests expression in the endoplasmic reticulum. When classified by neuronal size, large neurons (>1300 mum) showed higher levels of sigma1R staining than other groups (700-1300 mum,
Source: Molecular Pain - Category: Molecular Biology Authors: Source Type: research