Region-specific localization of glutamine synthetase immunoreactivity in the mouse olfactory bulb: implications for neuron-glia interaction in bulbarsynaptic plasticity

Glutamine synthetase (GS) critically regulates the metabolism of glutamate and gamma-amino butyric acid (GABA), which mediate synaptic plasticity in t he olfactory bulb. In this study, GS immunolocalization in the mouse olfact ory bulb wits examined. The main and accessory subdivisions of the olfactor y bulb possess GS-positive cells and processes in the plexiform-, the mitra l- and the granule cell layers. GS has been demonstrated to show a predomin antly astrocytic localization; its presence in the cell layers implicated i n glutamatergic and GABAergic function therefore suggests that bulbar synap tic plasticity in mice may be regulated by astroglia and, together with oth er lines of evidence, point to the possibility of a functional astroglia-ne uron system in the mouse olfactory bulb. (C) 2000 Elsevier Science B.V. All rights reserved.