Extracellular glutamate changes in rat striatum during ischemia determined by a novel dialysis electrode and conventional microdialysis

Sugahara, Megumi; Asai, Satoshi; Zhao, Heng; Nagata, Toshihito; Kunimatsu, Teruhito; Ishii, Yoshinori; Kohno, Tadashi; Ito, Koichi

doi:10.1016/s0197-0186(00)00109-1

Cited by 13 publications

(11 citation statements)

References 33 publications

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“…Sugahara et al . () reported a basal level of Glu in rat striatum of approximately 10 μM, which they obtained using a microdialysis electrode based on a biosensor; this value is similar to the result obtained here. However, it is important to consider several points when using microdialysis studies.…”

Section: Discussionsupporting

confidence: 89%

A microdialysis and enzymatic reactor sensing procedure for the simultaneous registration of online glutamate measurements at high temporal resolution during epileptiform activity

Morales‐Villagrán

Pardo-Peña

Medina‐Ceja

et al. 2016

Journal of Neurochemistry

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Glutamate measurement in microdialysis samples has primarily been determined using HPLC methods, and several attempts have been made to establish a relationship between this neurotransmitter and EEG activity during altered brain function, such as epilepsy. However, classic microdialysis methods lack high temporal resolution. In this study, a new alternative is proposed to improve the time resolution and thus obtain a better understanding of the dynamics of Glu and its relationship with epileptiform activity. A new setup was designed to measure Glu online in microdialysates using enzymatic reactors and fluorescence detection. In this study, we performed EEG recordings and Glu measurements simultaneously in the hippocampus to establish their relationship with the epileptiform events that are induced by pentylenetetrazole in intact and epileptic rats. Basal Glu levels in intact and animals with spontaneous seizures were not significantly different. However, a significant increase in Glu levels was detected during the first pentylenetetrazole-induced seizure in both groups. EEG analysis showed that the amplitude of epileptiform activity was higher in rats with spontaneous seizures and that the frequency of this activity did not change. The results showed that this method can be used to determine Glu changes at high temporal resolution and that these changes can be related to seizure activity. In addition, this method can also be used to measure other neurotransmitters that generate fluorescent derivatives. Moreover, this new technique has the following advantages compared with classical neurochemical methods: easy setup, low training requirements, no need for separation, rapidity, and the experimental data can be obtained and analysis performed in a single session.

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Section: Discussionsupporting

confidence: 89%

A microdialysis and enzymatic reactor sensing procedure for the simultaneous registration of online glutamate measurements at high temporal resolution during epileptiform activity

Morales‐Villagrán

Pardo-Peña

Medina‐Ceja

et al. 2016

Journal of Neurochemistry

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“…To reduce the time-limitation of microdialysis high timeresolution methods have been developed recently [17][18][19][20][21]. Applying extra-small internal diameter out-leading tubes and microbore chromatography of improved sensitivity allows analysis of samples in every 5 min and detection of femtomole/µl of GABA [11,19].…”

Section: Time-resolutionmentioning

confidence: 99%

“…In addition, coupling microdialysis and capillary electrophoresis with laser-induced fluorescence detection (CE-LIFD) could monitor samples in every 20 seconds with a 2 µl/min flow rate [18]. Besides these improvements of classical dialysis, methods using Gluselective dialysis electrodes or microelectrodes were able to detect changes in [Glu] EXT within a few seconds [20][21]. Whatever the improvement is, microdialysis is far from the time-resolution necessary to follow the synaptic release dynamics (milliseconds).…”

Section: Time-resolutionmentioning

confidence: 99%

“…Dramatic and rapid increases in [Glu] EXT and [GABA] EXT were measured by applying microdialysis and cortical cup techniques [20][21][57][58]. Depolarization-induced AA release from neurons contributes to initial accumulation of AA transmitters but Ca 2+ ionindependent mechanisms become dominant shortly after initiation of hypoxia [57][58].…”

Section: Cerebral Ischemiamentioning

confidence: 99%

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Extracellular Level of GABA and Glu: In Vivo Microdialysis-HPLC Measurements

Nyitrai¹,

Kékesi²,

Juhász

2006

CTMC

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In spite of several studies showing specific physiological functions of changes in the extracellular level of the major excitatory and inhibitory transmitters, Glu and GABA within the brain ([Glu](EXT), [GABA](EXT)) the exact origin (neuronal vs. astroglial, synaptic vs. extrasynaptic) of Glu and GABA present in dialysate samples is still a matter of debate. For better understanding the significance of in vivo microdialysis data, here we discuss methodological details and problems in addition to regulation of [Glu](EXT) and [GABA](EXT). Changes in [Glu](EXT) and [GABA](EXT) under pathological conditions such as ischemia and epilepsy are also reviewed. Based on recent in vivo microdialysis data we argue that ambient [Glu](EXT) and [GABA](EXT)may have a functional role. It is suggested that specific changes in concentrations of Glu and GABA in dialysate samples together with their alterations independent of neuronal activity indicate the involvement of Glu and GABA in the information processing of the brain as essential signaling molecules of nonsynaptic transmission as well. Since various drugs are able to interfere with extrasynaptic signals in vivo, studying the extracellular cell-to-cell communication of brain cells represents a new aspect to improve drugs modulating Gluergic as well as GABAergic neurotransmission.

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“…Abnormal transmission of glutamate can cause neurological diseases such as communication dysfunction, cognitive impairments, schizophrenia, Parkinson's disease, stroke and epilepsy 4,5 . Glutamate transformation in excitatory and neurovirulent processes has been studied for decades [6][7][8][9][10][11] . However, activity in the nervous system includes a complex combination of biochemical and electrical events in space and time [12][13][14] .…”

Section: Introductionmentioning

confidence: 99%

An implantable microelectrode array for simultaneous L-glutamate and electrophysiological recordings in vivo

et al. 2015

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L-glutamate, the most common excitatory neurotransmitter in the mammalian central nervous system (CNS), is associated with a wide range of neurological diseases. Because neurons in CNS communicate with each other both electrically and chemically, dualmode (electric and chemical) analytical techniques with high spatiotemporal resolution are required to better understand glutamate function in vivo. In the present study, a silicon-based implantable microelectrode array (MEA) composed of both platinum electrochemical and electrophysiological microelectrodes was fabricated using micro-electromechanical system. In the MEA probe, the electrophysiological electrodes have a low impedance of 0.018 MΩ at 1 kHz, and the electrochemical electrodes show a sensitivity of 56 pA µM −1 to glutamate and have a detection limit of 0.5 µM. The MEA probe was used to monitor extracellular glutamate levels, spikes and local field potentials (LFPs) in the striatum of anaesthetised rats. To explore the potential of the MEA probe, the rats were administered to KCl via intraperitoneal injection. K + significantly increases extracellular glutamate levels, LFP low-beta range (12-18 Hz) power and spike firing rates with a similar temporal profile, indicating that the MEA probe is capable of detecting dual-mode neuronal signals. It was concluded that the MEA probe can help reveal mechanisms of neural physiology and pathology in vivo.

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Extracellular glutamate changes in rat striatum during ischemia determined by a novel dialysis electrode and conventional microdialysis

Cited by 13 publications

References 33 publications

A microdialysis and enzymatic reactor sensing procedure for the simultaneous registration of online glutamate measurements at high temporal resolution during epileptiform activity

A microdialysis and enzymatic reactor sensing procedure for the simultaneous registration of online glutamate measurements at high temporal resolution during epileptiform activity

Extracellular Level of GABA and Glu: In Vivo Microdialysis-HPLC Measurements

An implantable microelectrode array for simultaneous L-glutamate and electrophysiological recordings in vivo

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