John J. Grigg

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Voltage-gated potassium (Kv) channels may play an important role in the encoding of auditory information. Towards understanding the roles of Shaker and Shaw-like channels in this process, we examine here the expression of Kv1.1, Kv1.2, Kv3.1, and Kv3.3 in the central auditory nuclei of the mouse using quantitative in situ hybridization techniques. We(More)
Effects of substance P on cultured neurons of the locus coeruleus of the rat were studied using the whole-cell patch clamp technique. In some cells substance P produced a decrease in a K conductance which showed an inwardly rectifying property. In other cells substance P produced an initial inward current which was accompanied by a conductance increase. The(More)
Intracellular recording during hypoxia in submerged hippocampal slices revealed an initial hyperpolarization with decreased membrane input resistance followed by complete depolarization. Glibenclamide (1 microM) reduced and tolbutamide (400 microM) completely blocked the hypoxic hyperpolarization and the accompanying increase in conductance. Neither(More)
1. In cultured rat locus coeruleus neurons, somatostatin or met-enkephalin induces an inwardly rectifying K+ conductance. This inward rectifier was analyzed at the single-channel level. 2. Using the inside-out patch-clamp, guanosine 5'-triphosphate (GTP) application to the cytoplasmic side in the presence of somatostatin or met-enkephalin in the pipette(More)
Margeta-Mitrovic, Marta, John J. Grigg, Konomi Koyano, Yader, because an excessive increase in the intracellular Ca suko Nakajima, and Shigehiro Nakajima. Neurotensin and subconcentration can lead to cellular degeneration and death stance P inhibit lowand high-voltage-activated Ca channels in (Choi 1988). cultured newborn rat nucleus basalis neurons. J.(More)
Voltage-gated K+ channels are localized to juxtaparanodal regions of myelinated axons. To begin to understand the role of normal compact myelin in this localization, we examined mKv1.1 and mKv1.2 expression in the dysmyelinating mouse mutants shiverer and Trembler. In neonatal wild-type and shiverer mice, the focal localization of both proteins in axon(More)
Inhibition of Ca2+ currents by the excitatory neurotransmitters neurotensin and substance P was investigated in cultured nucleus basalis neurons with the use of the whole cell patch-clamp technique. The whole cell Ca2+ current, elicited from a holding potential of -80 mV by a step pulse to 0 mV and measured at 100 ms, was inhibited 67.9% by neurotensin and(More)
Muscarine and somatostatin enhance an inward rectifier K+ conductance in the AtT-20 pituitary cell line. Both effects are abolished by pertussis toxin (PTX). To determine which PTX-sensitive G protein mediates these agonist effects, we made cDNAs encoding mutant PTX-insensitive Gi alpha subtypes, in which the cysteine residue fourth from the C terminus was(More)
Hippocampal slice survival after hypoxia was improved by exposure to competitive and noncompetitive N-methyl-D-aspartate (NMDA) antagonists. The rapid blockade and reappearance of synaptic transmission during hypoxia was not altered by these antagonists. However, [(+)-5-methyl-10, 11-dihydro-5H-dibenzo[a,d] cyclohepten-5, 10-imine maleate (MK-801) (50(More)
Somatostatin enhances an inward rectifier K conductance in cultured locus coeruleus neurons, while substance P reduces an inward rectifier K conductance in cultured nucleus basalis and locus coeruleus neurons. The role of arachidonic acid metabolites in these responses was studied. The somatostatin-induced response was reduced by phospholipase A2(More)