Details

Autor(en) / Beteiligte

• Morales-Villagrán, Alberto
• Beltrán-Ramírez, Raúl
• López-Pérez, Silvia J.
• Palomera-Ávalos, Verónica
• Medina-Ceja, Laura

Titel

A Capillary Fraction Collector Coupled to a Fluorescence Reader: A Novel Device to Continuously Quantify Glutamate During Microdialysis

Ist Teil von

• Neurochemical research, 2012-07, Vol.37 (7), p.1457-1464

Ort / Verlag

Boston: Springer US

Erscheinungsjahr

2012

Quelle

SpringerLink

Beschreibungen/Notizen

• Microdialysis coupled to HPLC is the preferred method for quantification of glutamate (Glu) concentrations, both in normal and pathological conditions. However, HPLC is a time consuming technique that suffers from poor temporal resolution. Here we describe an alternative method to measure glutamate concentrations in small-volume dialysis samples by quantifying hydrogen peroxide released by glutamate oxidase using the Amplex Red method. This system permits continuous automatic sample collection and the detection of a fluorescent reaction product, resorufin, which provides a measure of the glutamate concentration. Quantification can be carried out in small microdialysis samples to allow a temporal resolution of 60 s. Both in vitro and in vivo tests showed that this method was reproducible and reliable, detecting Glu along a linear scale. To validate the proposed method, extracellular Glu concentrations in the rat brain were measured and correlated with electrophysiological activity prior, during and after seizure induction with 4-aminopyridine. This method may be adapted to monitor other biologically active compounds, including acetylcholine and glucose, as well as other compounds that generate hydrogen peroxide as a reaction product and may be used as an alternative to other neurochemical methods.