Moshe Yarom

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We have recently shown that the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate enhances the depolarization induced, calcium dependent release of [3H]dopamine from cultured brain neurons in the rat. In the present study the effects of 12-O-tetradecanoyl-phorbol-13-acetate on the kinetic parameters of depolarization induced calcium influx and on Ca2+(More)
The permeability of neuronal membranes to Ca2+ is of great importance for neurotransmitter release. The temporal characteristics of Ca2+ fluxes in intact brain neurons have not been completely defined. In the present study 45Ca2+ was used to examine the kinetics of Ca2+ influx and efflux from unstimulated and depolarized rat brain neurons in culture. Under(More)
The coupling between depolarization-induced calcium entry and neurotransmitter release was studied in rat brain neurons in culture. The endogenous dopamine content of the cells was determined by high performance liquid chromatography utilizing electrochemical detection. The amount of dopamine in unstimulated cells was found to be about 16 ng/mg of protein.(More)
A membrane form of L-glutamate decarboxylase (GAD) was identified and purified to apparent homogeneity from hog brain. The purified GAD was established as an integral membrane protein by phase-partitioning assay, charge-shift electrophoresis, and chromatography on a hydrophobic interaction column. This membrane GAD has a native molecular mass of 96 +/- 5(More)
A new and novel form of L-glutamate decarboxylase (GAD; EC was purified from whole porcine brain to apparent homogeneity by a combination of column chromatographies on DE-52, ultragel AcA 34, hydroxylapatite and Sephadex G-200, and native gel electrophoresis. The purified GAD was established as an integral membrane protein based on hydrophobic(More)
The neurotoxic effects of various glutamate agonists were studied using whole fetal rat brain cultures. The results showed that L-glutamate (L-glu) and N-methyl-D-aspartate (NMDA) were the most potent agonists for inducing neurotoxicity, producing significant toxicity at 0.10 and 0.01 mM concentrations, respectively. Kainic acid (KA) and quisqualic acid(More)
Pig brain extracts from both soluble and membrane fractions were found to contain potent inhibitors for GABA synthesizing enzyme, GAD, referred to as endogenous GAD inhibitors (EGIs) and for the binding of GABA agonist, muscimol, referred to as muscimol binding inhibitors (MBIs). EGIs and MBIs were first purified through gel-filtration Bio-Gel P-2 columns,(More)
Several endogenous brain substances which inhibit [3H]muscimol binding were isolated, and one of them has been purified to apparent homogeneity. The purification involved the extraction of brain tissue with water, followed by several steps of gel filtration column chromatography and high performance liquid chromatography (HPLC). The muscimol binding(More)
Previously we have reported the presence of endogenous ligands that are involved in the regulation of the binding of muscimol to the GABA binding site of the GABAA receptors. Here, we report the presence of multiple forms of endogenous ligands in the brain which modulate the binding of flunitrazepam (FNZP) to the benzodiazepine (BZ) binding site of the(More)