Two Signal Transduction Mechanisms of Substance P‐induced Depolarization in Locus Coeruleus Neurons
- 1 September 1993
- journal article
- Published by Wiley in European Journal of Neuroscience
- Vol. 5 (9), 1189-1197
- https://doi.org/10.1111/j.1460-9568.1993.tb00973.x
Abstract
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 rest of the cells showed responses which were mixtures of the above two responses. The measurement of the reversal potential of the initial inward current after suppressing the voltage‐gated Ca and K conductances suggests that it is caused by an increase in a non‐selective ionic conductance. In cells loaded with 260 μM GTPγS, application of substance P produced an irreversible reduction of the K conductance, while the initial inward current could still be recorded, suggesting that the former is mediated by a G protein, whereas the latter may be activated by a different signal transduction mechanism. The initial inward current was not eliminated by external application of high concentrations of tetrodotoxin, d‐tubocurarine or amiloride. Nor was it affected by the intracellular application of cyclic GMP or cyclic AMP.Keywords
This publication has 50 references indexed in Scilit:
- Substance P and somatostatin inhibit calcium channels in rat sympathetic neurons via different G protein pathwavsNeuron, 1993
- Molecular Characterization of a Functional cDNA Encoding the Rat Substance P ReceptorScience, 1990
- Amiloride and its analogs as tools in the study of ion transportThe Journal of Membrane Biology, 1988
- G PROTEINS: TRANSDUCERS OF RECEPTOR-GENERATED SIGNALSAnnual Review of Biochemistry, 1987
- Substance P and pain: an updatingTrends in Neurosciences, 1980
- Studies on rat sympathetic neurons developing in cell cultureDevelopmental Biology, 1978
- Does substance P mediate slow synaptic excitation within the myenteric plexus?Nature, 1978
- Excitation of neurons in the nucleus locus coeruleus by substance P and related peptidesBrain Research, 1977
- ANALYSIS OF THE SLOW EXCITATORY POSTSYNAPTIC POTENTIAL IN BULLFROG SYMPATHETIC GANGLION CELLSThe Japanese Journal of Physiology, 1976
- Biogenic Amines and Active Polypeptides of the Amphibian SkinAnnual Review of Pharmacology, 1971