Immunoreactivity of glutamine synthetase in satellite glia around various subpopulations of lumbar dorsal root ganglia neurons in adult rats treated with monosodium glutamate

• Published in: Journal of chemical neuroanatomy 2023-12, Vol.134, p.102347-102347, Article 102347
• Main Authors: Krawczyk, Aleksandra, Mozel, Sylwia, Rycerz, Karol, Jaworska-Adamu, Jadwiga, Arciszewski, Marcin Bartłomiej
• Format: Article
• Language: English
• Subjects: DRG; Glutamine synthetase; MSG; Satellite glial cells; Substance P
• ISSN: 0891-0618; 1873-6300
• DOI: 10.1016/j.jchemneu.2023.102347

Satellite glial cells (SGCs), involved inter alia in glutamate (Glu) metabolism, form a glial sheath around sensory neurons of dorsal root ganglia (DRGs). SGCs show a presence of glutamine synthetase (GS) which transform uptaken Glu into glutamine (Gln). In DRGs, this aminoacid is used mainly by small neurons which are able to synthetize substance P (SP) that play a crucial role in nociception. The aim of the study was to define the influence of monosodium glutamate (MSG) on GS immunoreactivity in satellite glia around various subpopulations of neurons including SP immunopositive cells in DRGs of adult rats. The studies were carried out on lumbar DRGs slides in rats which received subcutaneous injection of saline solution (control group) or 4 g/kg b. w. of MSG (MSG group). Immunofluorescence reactions were conducted with use of anti-GS and anti-SP antibodies. Administration of MSG to adult rats increased the GS immunoexpression in SGCs. In rats receiving MSG, a number of small neurons with GS-immunopositive glial sheath was not altered when compared to control individuals, whereas there was a statistically significant increase of GS immunoexpression in SGCs around large and medium neurons. Moreover, in these animals, a statistically significant increase in the number of small SP-positive neurons with GS-positive glial sheath was observed. SP is responsible for transmission of pain, thus the obtained results may be useful for further research concerning the roles of glia in nociceptive pathway regulation. •Administration of MSG to adult rats increased the GS immunoexpression in SGCs of lumbar DRGs.•There was the increase of GS-IR glial cells around large and medium neurons but not around small neurons.•An increase in the number of small SP-positive neurons with GS-positive glial sheath was demonstrated.•The obtained results may be useful for further research concerning the roles of glia in nociceptive pathway regulation.