Diversity among satellite glial cells in dorsal root ganglia of the rat

Abstract

Peripheral glial cells consist of satellite, enteric glial, and Schwann cells. In dorsal root ganglia, besides pseudo-unipolar neurons, myelinated and nonmyelinated fibers, macrophages, and fibroblasts, satellite cells also constitute the resident components. Information on satellite cells is not abundant; however, they appear to provide mechanical and metabolic support for neurons by forming an envelope surrounding their cell bodies. Although there is a heterogeneous population of neurons in the dorsal root ganglia, satellite cells have been described to be a homogeneous group of perineuronal cells. Our objective was to characterize the ultrastructure, immunohistochemistry, and histochemistry of the satellite cells of the dorsal root ganglia of 17 adult 3-4-month-old Wistar rats of both genders. Ultrastructurally, the nuclei of some satellite cells are heterochromatic, whereas others are euchromatic, which may result from different amounts of nuclear activity. We observed positive immunoreactivity for S-100 and vimentin in the cytoplasm of satellite cells. The intensity of S-100 protein varied according to the size of the enveloped neuron. We also noted that vimentin expression assumed a ring-like pattern and was preferentially located in the cytoplasm around the areas stained for S-100. In addition, we observed nitric oxide synthase-positive small-sized neurons and negative large-sized neurons equal to that described in the literature. Satellite cells were also positive for NADPH-diaphorase, particularly those associated with small-sized neurons. We conclude that all satellite cells are not identical as previously thought because they have different patterns of glial marker expression and these differences may be correlated with the size and function of the neuron they envelope.

HMG-CoA synthase isoenzymes 1 and 2 localize to satellite glial cells in dorsal root ganglia and are differentially regulated by peripheral nerve injury

“…Their immunopositivity was colabeled with a variety of specific SGC proteins, indicating that HMGCSs may function as ‘housekeeping’ molecules in the diverse SGC populations (Nascimento et al, 2008). Although weakly detected in the periaxonal glial cells in the spinal nerve and root segments, HMGCSs were not found in spinal cord and peripheral nerve terminals, suggesting that the major function of HMGCSs may not be associated with myelin formation.…”

Dual Effect of Methylglyoxal on the Intracellular Ca2+ Signaling and Neurite Outgrowth in Mouse Sensory Neurons

“…A large variety of cells reside in mammalian DRGs, such as pseudo-unipolar neurons, myelinated, and non-myelinated fibers, macrophages, fibroblasts, and satellite perineuronal cells (Nascimento et al 2008). Mouse sensory neurons have a wide heterogeneity, their cross-sectional area varying between small neurons (\600 lm 2 ), medium neurons (60071,200 lm 2 ), and large neurons ([1,200 lm 2 ) (Ren et al 2012).…”

Growth/differentiation factor-15 and its role in peripheral nervous system lesion and regeneration

“…bodies within ganglia, and are considered to have various functions, such as nutrients supply, protection, and microenvironment control (Fex et al, 2004;Nascimento et al, 2008;Pannese, 2010).…”