Excitatory action of N-acetylaspartylglutamate on Purkinje cells in guinea pig cerebellar slices: an intrasomatic study. 1987

M Sekiguchi, and K Okamoto, and Y Sakai
Department of Pharmacology, National Defense Medical College, Saitama, Japan.

The action of N-acetylaspartylglutamate (NAAG) on Purkinje cell somata in guinea pig cerebellar slices was intracellularly investigated in comparison with L-aspartate (Asp) and L-glutamate (Glu). A synthetic NAAG sample used was confirmed not to be contaminated with free Glu and Asp. NAAG, applied by either iontophoresis or superfusion, dose-dependently depolarized Purkinje cell somata, and iontophoretically applied NAAG decreased the membrane resistance in voltage- and Mg2+-dependent manners, like Asp or Glu. Relative depolarizing potencies seemed to be Glu greater than NAAG not equal to Asp in the presence of external Mg2+ and Asp greater than NAAG greater than or equal to Glu in the absence of Mg2+. In addition to this selective blocking effect of Mg2+, 2-amino-5-phosphonovalerate (APV) antagonized the actions of NAAG and Asp more strongly than that of Glu, while 2-amino-4-phosphonobutyrate showed rather non-selective antagonisms. The reversal potential of the NAAG action was at about 10 mV and similar to that of the action of Asp or Glu. These results suggest that NAAG itself is excitatory to guinea pig cerebellar Purkinje cells and is likely to be acting on Asp- and APV-sensitive, Mg2+-dependent receptors on cerebellar Purkinje cells.

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
D008274 Magnesium A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008297 Male Males
D008564 Membrane Potentials The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization). Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D011689 Purkinje Cells The output neurons of the cerebellar cortex. Purkinje Cell,Purkinje Neuron,Purkyne Cell,Cell, Purkinje,Cell, Purkyne,Cells, Purkinje,Cells, Purkyne,Neuron, Purkinje,Neurons, Purkinje,Purkinje Neurons,Purkyne Cells
D002531 Cerebellum The part of brain that lies behind the BRAIN STEM in the posterior base of skull (CRANIAL FOSSA, POSTERIOR). It is also known as the "little brain" with convolutions similar to those of CEREBRAL CORTEX, inner white matter, and deep cerebellar nuclei. Its function is to coordinate voluntary movements, maintain balance, and learn motor skills. Cerebella,Corpus Cerebelli,Parencephalon,Cerebellums,Parencephalons
D002851 Chromatography, High Pressure Liquid Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed. Chromatography, High Performance Liquid,Chromatography, High Speed Liquid,Chromatography, Liquid, High Pressure,HPLC,High Performance Liquid Chromatography,High-Performance Liquid Chromatography,UPLC,Ultra Performance Liquid Chromatography,Chromatography, High-Performance Liquid,High-Performance Liquid Chromatographies,Liquid Chromatography, High-Performance
D004151 Dipeptides Peptides composed of two amino acid units. Dipeptide
D005971 Glutamates Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure. Glutamic Acid Derivatives,Glutamic Acids,Glutaminic Acids
D006168 Guinea Pigs A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research. Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea

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