Spatio-temporal characteristics of metabotropic glutamate receptor 5 traffic at or near the plasma membrane in astrocytes

Academic Article

Abstract

  • © 2016 Wiley Periodicals, Inc. Astrocytes can sense extracellular glutamate and respond to it by elevating their intracellular Ca2+ levels via the activation of G-protein coupled receptors, such as metabotropic glutamate receptor 5 (mGluR5), which, during early postnatal development, is the primary receptor responsible for glutamatergic signaling in astrocytes. However, the detailed spatio-temporal characteristics of mGluR5 traffic at or near the plasma membrane of astrocytes are not well understood. To address this issue, we expressed recombinant fluorescent protein chimera of mGluR5 and used total internal reflection fluorescence microscopy on rat visual cortical astrocytes in culture. We used astrocytes lacking major processes, otherwise posing as a diffusion barrier, to infer into the general dynamics of this receptor. We found that plasmalemmal mGluR5 clusters in distinct areas, the size, and initial spatio-temporal level of occupancy of which dictated mGluR5 trafficking characteristics upon glutamate stimulation. These findings will be valuable in the interpretation of point-to-point information transfer and volume transmission between astrocytes and neurons, as well as that of paracrine signaling within astrocytic networks. GLIA 2016;64:1050-1065 Main Points: mGluR5 clusters in distinct areas of the astrocytic plasma membrane. The size and initial level of spatio-temporal occupancy of mGluR5 clusters dictate mGluR5 trafficking characteristics upon glutamate stimulation.
  • Published In

  • Glia  Journal
  • Digital Object Identifier (doi)

    Author List

  • Lee W; Parpura V
  • Start Page

  • 1050
  • End Page

  • 1065
  • Volume

  • 64
  • Issue

  • 6