Comparison of the L-glutamate level in mouse hippocampal slices under tetraethylammonium chloride stimulation as measured with a glass capillary sensor and a patch sensor.
The concentration level of L-glutamate released from the region CA1 of mouse hippocampal slices under tetraethylammonium chloride (TEA) stimulation was measured by two independent methods, i.e., a glass capillary-based enzyme sensor and a patch sensor, and compared with each other for different slice preparations. In a submerged slice preparation, the sensors were positioned in bath solutions several tens microm above CA1, respectively. The sensors exhibited almost the same level of extra-slice L-glutamate concentration. When a capillary sensor was implanted in region CA1 at a depth of approximately 10 microm, the TEA-induced L-glutamate release pattern was very similar to those observed with the capillary sensor in a bath use. The concentration level of intra-slice (extracellular) L-glutamate was found to be in the range from 6 to 10 microM, which was significantly larger than that of the extra-slice one. These results demonstrate that L-glutamate released from each neuronal region inevitably diffuses out of the slices, and the extra-slice L-glutamate level reflects the extracellular one.
Oka
Takayuki
T
Department of Chemistry, College of Humanities and Sciences, Nihon University, Sakurajosui, Setagaya, Tokyo 156-8550, Japan.
Tominaga
Yumiko
Y
Wakabayashi
Yuichiro
Y
Shoji
Atsushi
A
Sugawara
Masao
M
D000818:Animals; D001204:Ascorbate Oxidase / Q000378:metabolism; D015374:Biosensing Techniques / Q000379:methods*; D005971:Glutamates / Q000032:analysis*; D006624:Hippocampus / Q000737:chemistry*; D008297:Male; D051379:Mice; D018408:Patch-Clamp Techniques; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019789:Tetraethylammonium / Q000737:chemistry*; D013997:Time Factors
D005971:Glutamates; D019789:Tetraethylammonium; D001204:Ascorbate Oxidase