The Journal of Neuroscience : The Official Journal of the Society for Neuroscience
Neuronal acetylcholine receptors, being highly permeable to calcium, are likely to regulate calci... more Neuronal acetylcholine receptors, being highly permeable to calcium, are likely to regulate calcium-dependent events in neurons. Arachidonic acid is a membrane-permeant second messenger that can be released from membrane phospholipids by phospholipases in a calcium-dependent manner. We show here that activation of neuronal acetylcholine receptors triggers release of 3H-arachidonic acid in a calcium-dependent manner from neurons preloaded with the fatty acid. Moreover, low concentrations of arachidonic acid reversibly inhibit the receptors and act most efficiently on receptors likely to have the highest permeability to calcium, namely receptors containing alpha 7 subunits. Low concentrations of arachidonic acid also reversibly inhibit alpha 7-containing receptors expressed in Xenopus oocytes following injection of alpha 7 cRNA. The oocyte results indicate following injection of alpha 7 cRNA. The oocyte results indicate that the inhibition is a feature of the receptors rather than a c...
The Journal of Neuroscience : The Official Journal of the Society for Neuroscience
A major class of nicotinic receptors in the nervous system is one that binds alpha-bungarotoxin a... more A major class of nicotinic receptors in the nervous system is one that binds alpha-bungarotoxin and contains the alpha7 gene product. PC12 cells, frequently used to study nicotinic receptors, express the alpha7 gene and have binding sites for the toxin, but previous attempts to elicit currents from the putative receptors have failed. Using whole-cell patch-clamp recording techniques and rapid application of agonist, we find a rapidly desensitizing acetylcholine-induced current in the cells that can be blocked by alpha-bungarotoxin. The current amplitude varies dramatically among three populations of PC12 cells but correlates well with the number of toxin-binding receptors. In contrast, the current shows no correlation with alpha7 transcript; cells with high levels of alpha7 mRNA can be negative for toxin binding and yet have other functional nicotinic receptors. Northern blot analysis and reverse transcription-PCR reveal no defects in alpha7 RNA from the negative cells, and immunobl...
A major class of nicotinic receptors in the nervous system is one that binds a-bungarotoxin and c... more A major class of nicotinic receptors in the nervous system is one that binds a-bungarotoxin and contains the a7 gene prod- uct. PC12 cells, frequently used to study nicotinic receptors, express the a7 gene and have binding sites for the toxin, but previous attempts to elicit currents from the putative receptors have failed. Using whole-cell patch-clamp recording tech- niques and
Sukumar Vijayaraghavan, Bo Huang, Edward M. Blumenthal, and Darwin K. Berg Department of Biology,... more Sukumar Vijayaraghavan, Bo Huang, Edward M. Blumenthal, and Darwin K. Berg Department of Biology, University of California at San Diego, La Jolla, California 92093-0357 ... Neuronal acetylcholine receptors, being highly permeable to calcium, are likely to regulate calcium-...
The Journal of Neuroscience : The Official Journal of the Society for Neuroscience
Neuronal acetylcholine receptors, being highly permeable to calcium, are likely to regulate calci... more Neuronal acetylcholine receptors, being highly permeable to calcium, are likely to regulate calcium-dependent events in neurons. Arachidonic acid is a membrane-permeant second messenger that can be released from membrane phospholipids by phospholipases in a calcium-dependent manner. We show here that activation of neuronal acetylcholine receptors triggers release of 3H-arachidonic acid in a calcium-dependent manner from neurons preloaded with the fatty acid. Moreover, low concentrations of arachidonic acid reversibly inhibit the receptors and act most efficiently on receptors likely to have the highest permeability to calcium, namely receptors containing alpha 7 subunits. Low concentrations of arachidonic acid also reversibly inhibit alpha 7-containing receptors expressed in Xenopus oocytes following injection of alpha 7 cRNA. The oocyte results indicate following injection of alpha 7 cRNA. The oocyte results indicate that the inhibition is a feature of the receptors rather than a c...
The Journal of Neuroscience : The Official Journal of the Society for Neuroscience
A major class of nicotinic receptors in the nervous system is one that binds alpha-bungarotoxin a... more A major class of nicotinic receptors in the nervous system is one that binds alpha-bungarotoxin and contains the alpha7 gene product. PC12 cells, frequently used to study nicotinic receptors, express the alpha7 gene and have binding sites for the toxin, but previous attempts to elicit currents from the putative receptors have failed. Using whole-cell patch-clamp recording techniques and rapid application of agonist, we find a rapidly desensitizing acetylcholine-induced current in the cells that can be blocked by alpha-bungarotoxin. The current amplitude varies dramatically among three populations of PC12 cells but correlates well with the number of toxin-binding receptors. In contrast, the current shows no correlation with alpha7 transcript; cells with high levels of alpha7 mRNA can be negative for toxin binding and yet have other functional nicotinic receptors. Northern blot analysis and reverse transcription-PCR reveal no defects in alpha7 RNA from the negative cells, and immunobl...
A major class of nicotinic receptors in the nervous system is one that binds a-bungarotoxin and c... more A major class of nicotinic receptors in the nervous system is one that binds a-bungarotoxin and contains the a7 gene prod- uct. PC12 cells, frequently used to study nicotinic receptors, express the a7 gene and have binding sites for the toxin, but previous attempts to elicit currents from the putative receptors have failed. Using whole-cell patch-clamp recording tech- niques and
Sukumar Vijayaraghavan, Bo Huang, Edward M. Blumenthal, and Darwin K. Berg Department of Biology,... more Sukumar Vijayaraghavan, Bo Huang, Edward M. Blumenthal, and Darwin K. Berg Department of Biology, University of California at San Diego, La Jolla, California 92093-0357 ... Neuronal acetylcholine receptors, being highly permeable to calcium, are likely to regulate calcium-...
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Papers by Edward Blumenthal