Simultaneous monitoring of amperometric currents at a glass capillary sensor based on recombinant GluOx and field excitatory postsynaptic potentials (fEPSPs) were performed in region CA1 of mouse hippocampal slices. A transient increase in the glutamate current relative to the basal one at control stimulation (0.052. Hz) was evoked by stimulation at 2. Hz for 2. min. The magnitude of the glutamate current was dependent on the intensity (current) of a 2. Hz stimulus and reflected the slope of the fEPSP. The in situ calibration of the l-glutamate sensor revealed that the extracellular concentration of l-glutamate released by 2. Hz stimulation before tetanus is in the range from 0.8 to 2.2. μM and it is enhanced after tetanic stimulation. The l-glutamate level at a test stimulus (0.052. Hz) was estimated to be 32. nM. The recombinant GluOx-based sensor exhibited weak responses to glutamine above 300. μM and l-aspartic acid above 200. μM. The potential use of a glass capillary sensor in combination with fEPSP measurements for electrophysiological study is discussed.
- Field excitatory postsynaptic potentials
- Glutamate currents
- Mouse hippocampal slice
ASJC Scopus subject areas
- Biomedical Engineering