Abstract
Muscarinic excitation of sympathetic ganglion cells has usually been thought to result from inhibition of an outward K+ current, the M current, although in other neurones several conductances have been shown to be blocked by muscarinic agonists. We report that, as well as resting K+ conductance, all of four different K+ conductances, two voltage-dependent (M currents and A currents) and two calcium-dependent (responsible for slow and very slow afterhyperpolarizations), present in different sub-types of guinea-pig sympathetic neurones, are inhibited by the muscarinic agonists, bethanechol and muscarine. All of these effects increase neurone excitability and can lead to repetitive discharge.
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Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Adams P. R., Brown D. A., Constanti A. M-currents and other potassium currents in bullfrog sympathetic neurones. J Physiol. 1982 Sep;330:537–572. doi: 10.1113/jphysiol.1982.sp014357. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Belluzzi O., Sacchi O., Wanke E. Identification of delayed potassium and calcium currents in the rat sympathetic neurone under voltage clamp. J Physiol. 1985 Jan;358:109–129. doi: 10.1113/jphysiol.1985.sp015543. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brown D. A., Constanti A. Intracellular observations on the effects of muscarinic agonists on rat sympathetic neurones. Br J Pharmacol. 1980 Dec;70(4):593–608. doi: 10.1111/j.1476-5381.1980.tb09778.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cassell J. F., Clark A. L., McLachlan E. M. Characteristics of phasic and tonic sympathetic ganglion cells of the guinea-pig. J Physiol. 1986 Mar;372:457–483. doi: 10.1113/jphysiol.1986.sp016020. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Constanti A., Brown D. A. M-Currents in voltage-clamped mammalian sympathetic neurones. Neurosci Lett. 1981 Jul 17;24(3):289–294. doi: 10.1016/0304-3940(81)90173-7. [DOI] [PubMed] [Google Scholar]
- Galvan M., Sedlmeir C. Outward currents in voltage-clamped rat sympathetic neurones. J Physiol. 1984 Nov;356:115–133. doi: 10.1113/jphysiol.1984.sp015456. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jänig W., Krauspe R., Wiedersatz G. Reflex activation of postganglionic vasoconstrictor neurones supplying skeletal muscle by stimulation of arterial chemoreceptors via non-nicotinic synaptic mechanisms in sympathetic ganglia. Pflugers Arch. 1983 Feb;396(2):95–100. doi: 10.1007/BF00615511. [DOI] [PubMed] [Google Scholar]
- Kobayashi H., Libet B. Actions of noradrenaline and acetylcholine on sympathetic ganglion cells. J Physiol. 1970 Jun;208(2):353–372. doi: 10.1113/jphysiol.1970.sp009125. [DOI] [PMC free article] [PubMed] [Google Scholar]
- North R. A., Tokimasa T. Depression of calcium-dependent potassium conductance of guinea-pig myenteric neurones by muscarinic agonists. J Physiol. 1983 Sep;342:253–266. doi: 10.1113/jphysiol.1983.sp014849. [DOI] [PMC free article] [PubMed] [Google Scholar]