Implantation of a glass capillary-based enzyme electrode in mouse hippocampal slices for monitoring of L-glutamate release.
A glass capillary-based enzyme electrode (tip size approximately 10 microm) was implanted in the target neuronal region, i.e., dentate gyrus (DG) or cornu ammonis 1 (CA1), of acute brain slices at a depth of approximately 10 microm from the slice surface in order to allow the monitoring of chemical stimulant-induced changes in L-glutamate levels. First, the sampling behavior of a glass capillary in a slice was investigated by visualizing the transport of a fluorescence dye. Then, the electrode was applied to real-time monitoring of L-glutamate release in acute hippocampal slices stimulated by surface application of a stimulant solution. The extracellular application of KCl (0.10 M) increased the glutamate levels in the DG and CA1 regions, respectively. The enhancement of L-glutamate concentration at DG was much larger than at CA1. The application of tetraethylammonium chloride (TEA) (25 mM) enhanced the L-glutamate level in the DG region and the enhanced level did not return to the initial value before TEA application even when washed with an artificial cerebrospinal fluid (ACSF). The usefulness of a surface-implanted capillary electrode for monitoring L-glutamate release in acute brain slices is discussed.
Oka
Takayuki
T
Department of Chemistry, College of Humanities and Sciences, Nihon University, Sakurajousui, Setagaya, Tokyo, 156-8550, Japan.
Tasaki
Chihiro
C
Sezaki
Hiromi
H
Sugawara
Masao
M
D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D001923:Brain Chemistry; D018698:Glutamic Acid / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D051379:Mice; D008839:Microelectrodes; D008867:Microtomy; D011189:Potassium Chloride / Q000494:pharmacology
D018698:Glutamic Acid; D011189:Potassium Chloride