Estimating the glutamate transporter surface density in distinct sub-cellular compartments of mouse hippocampal astrocytes

Authors

Annalisa Scimemi, University at Albany, State University of New York
Damian G. Zuloaga, University at Albany, State University of New York
Ashley M. Kopec, Albany Medical College
Justin R. Bourgeois, Albany Medical College
Haley E. Chesbro, University at Albany, State University of New York
Alex A. Lemus, University at Albany, State University of New York
Benjamin A. Bennink, University at Albany, State University of New York
Cassandra L. Williams, State University of New York College at New Paltz
Gabrielle C. Todd, University at Albany, State University of New York
Anca R. Radulescu, State University of New York College at New Paltz

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Document Type

Article

Publication Date

2-4-2022

DOI

https://doi.org/10.1371/journal.pcbi.1009845 See t

Abstract

Glutamate transporters preserve the spatial specificity of synaptic transmission by limiting glutamate diffusion away from the synaptic cleft, and prevent excitotoxicity by keeping the extracellular concentration of glutamate at low nanomolar levels. Glutamate transporters are abundantly expressed in astrocytes, and previous estimates have been obtained about their surface expression in astrocytes of the rat hippocampus and cerebellum. Analogous estimates for the mouse hippocampus are currently not available. In this work, we derive the surface density of astrocytic glutamate transporters in mice of different ages via quantitative dot blot. We find that the surface density of glial glutamate transporters is similar in 7-8 week old mice and rats. In mice, the levels of glutamate transporters increase until about 6 months of age and then begin to decline slowly. Our data, obtained from a combination of experimental and modeling approaches, point to the existence of stark differences in the density of expression of glutamate transporters across different sub-cellular compartments, indicating that the extent to which astrocytes limit extrasynaptic glutamate diffusion depends not only on their level of synaptic coverage, but also on the identity of the astrocyte compartment in contact with the synapse. Together, these findings provide information on how heterogeneity in the spatial distribution of glutamate transporters in the plasma membrane of hippocampal astrocytes my alter glutamate receptor activation out of the synaptic cleft.

Comments

This is the Publisher’s PDF of the following article made available by PLoS Computational Biology: Rǎdulescu AR, Todd GC, Williams CL, Bennink BA, Lemus AA, et al. (2022) Estimating the glutamate transporter surface density in distinct sub-cellular compartments of mouse hippocampal astrocytes. PLOS Computational Biology 18(2): e1009845. https://doi.org/10.1371/journal.pcbi.1009845

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Scimemi, Annalisa; Zuloaga, Damian G.; Kopec, Ashley M.; Bourgeois, Justin R.; Chesbro, Haley E.; Lemus, Alex A.; Bennink, Benjamin A.; Williams, Cassandra L.; Todd, Gabrielle C.; and Radulescu, Anca R., "Estimating the glutamate transporter surface density in distinct sub-cellular compartments of mouse hippocampal astrocytes" (2022). Biological Sciences Faculty Scholarship. 40.
https://scholarsarchive.library.albany.edu/biology_fac_scholar/40