Real-time monitoring of extracellular adenosine using enzyme-linked microelectrode arrays

Jason M. Hinzman, Justin L. Gibson, Ryan D. Tackla, Mark S. Costello, Jason J. Burmeister, Jorge E. Quintero, Greg A. Gerhardt, Jed A. Hartings

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

Throughout the central nervous system extracellular adenosine serves important neuroprotective and neuromodulatory functions. However, current understanding of the in vivo regulation and effects of adenosine is limited by the spatial and temporal resolution of available measurement techniques. Here, we describe an enzyme-linked microelectrode array (MEA) with high spatial (7500μm2) and temporal (4Hz) resolution that can selectively measure extracellular adenosine through the use of self-referenced coating scheme that accounts for interfering substances and the enzymatic breakdown products of adenosine. In vitro, the MEAs selectively measured adenosine in a linear fashion (r2=0.98±0.01, concentration range=0-15μM, limit of detection =0.96±0.5μM). In vivo the limit of detection was 0.04±0.02μM, which permitted real-time monitoring of the basal extracellular concentration in rat cerebral cortex (4.3±1.5μM). Local cortical injection of adenosine through a micropipette produced dose-dependent transient increases in the measured extracellular concentration (200nL: 6.8±1.8μM; 400nL: 19.4±5.3μM) [P<0.001]. Lastly, local injection of dipyridamole, which inhibits transport of adenosine through equilibrative nucleoside transporter, raised the measured extracellular concentration of adenosine by 120% (5.6→12.3μM) [P<0.001]. These studies demonstrate that MEAs can selectively measure adenosine on temporal and spatial scales relevant to adenosine signaling and regulation in normal and pathologic states.

Original languageEnglish
Pages (from-to)512-517
Number of pages6
JournalBiosensors and Bioelectronics
Volume74
DOIs
StatePublished - Dec 5 2015

Bibliographical note

Publisher Copyright:
© 2015 Elsevier B.V.

Keywords

  • Amperometry
  • Microdialysis
  • Voltammetry

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry

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