TTX-sensitive Na+ channels and Ca2+ channels of the L- and N-type underlie the inward current in acutely dispersed coeliac-mesenteric ganglia neurons of adult rats
- PMID: 1321408
- DOI: 10.1007/BF00374726
TTX-sensitive Na+ channels and Ca2+ channels of the L- and N-type underlie the inward current in acutely dispersed coeliac-mesenteric ganglia neurons of adult rats
Abstract
Inward membrane currents of sympathetic neurons acutely dispersed from coeliac-superior mesenteric ganglia (C-SMG) of adult rats were characterized using the whole-cell variant of the patch-clamp technique. Current-clamp studies indicated that C-SMG neurons retained electrical properties similar to intact ganglia. Voltage-clamp studies designed to isolate Na+ currents revealed that tetrodotoxin (TTX, 1 microM) completely inhibited the large transient inward current. Half activation potential (Vh) and slope factor (K) were -26.8 mV and 6.1 mV, respectively. Inactivation parameters for Vh and K were -65 mV and 8.2 mV, respectively. Voltage-clamp studies also revealed a high-voltage-activated sustained inward Ca2+ current which was blocked by the removal of external Ca2+ or the presence of Cd2+ (0.1 mM). The dihydropyridine agonist, (+)202-791 (1 microM), caused a small increase (20%) in the amplitude of the Ca2+ current at more negative potentials and markedly prolonged the tail currents. omega-Conotoxin GIVA (omega, CgTX, 15 microM) caused a 66% inhibition of the high-voltage-activated Ca2+ current amplitude. Norepinephrine (1 microM) caused a 49% reduction in the peak Ca2+ current. This study is the first demonstration that dispersed C-SMG neurons from adult rats retain electrical characteristics similar to intact ganglia. A TTX-sensitive Na+ current as well as a high voltage-activated sustained Ca2+ current underlie the inward current in C-SMG neurons. The macroscopic Ca2+ current is composed of a small dihydropyridine-sensitive (L-type current) and a large omega-CgTx-sensitive (N-type current) component.(ABSTRACT TRUNCATED AT 250 WORDS)
Similar articles
-
Voltage-dependent sodium and calcium currents in acutely isolated adult rat trigeminal root ganglion neurons.J Neurophysiol. 1999 Mar;81(3):1123-34. doi: 10.1152/jn.1999.81.3.1123. J Neurophysiol. 1999. PMID: 10085339
-
Inward membrane currents and electrophysiological responses to GnRH in ovine gonadotropes.Neuroendocrinology. 1995 Jun;61(6):609-21. doi: 10.1159/000126887. Neuroendocrinology. 1995. PMID: 7544876
-
Na+ and Ca2+ currents of acutely isolated adult rat nodose ganglion cells.J Neurophysiol. 1986 Mar;55(3):527-39. doi: 10.1152/jn.1986.55.3.527. J Neurophysiol. 1986. PMID: 2420945
-
Tetrodotoxin-resistant sodium channels.Cell Mol Neurobiol. 1994 Jun;14(3):227-44. doi: 10.1007/BF02088322. Cell Mol Neurobiol. 1994. PMID: 7712513 Review.
-
Neuroprotection--rationale for pharmacological modulation of Na(+)-channels.Amino Acids. 1998;14(1-3):151-8. doi: 10.1007/BF01345256. Amino Acids. 1998. PMID: 9871455 Review.
Cited by
-
Phenotype-specific expression of T-type calcium channels in neurons of the major pelvic ganglion of the adult male rat.J Physiol. 1995 Dec 1;489 ( Pt 2)(Pt 2):363-75. doi: 10.1113/jphysiol.1995.sp021057. J Physiol. 1995. PMID: 8847632 Free PMC article.
-
Encoding properties induced by a persistent voltage-gated muscarinic sodium current in rabbit sympathetic neurones.J Physiol. 1998 Jul 15;510 ( Pt 2)(Pt 2):387-99. doi: 10.1111/j.1469-7793.1998.387bk.x. J Physiol. 1998. PMID: 9705991 Free PMC article.
-
Potassium currents in rat prevertebral and paravertebral sympathetic neurones: control of firing properties.J Physiol. 1995 Jun 1;485 ( Pt 2)(Pt 2):319-35. doi: 10.1113/jphysiol.1995.sp020732. J Physiol. 1995. PMID: 7666361 Free PMC article.
-
Gα14 subunit-mediated inhibition of voltage-gated Ca2+ and K+ channels via neurokinin-1 receptors in rat celiac-superior mesenteric ganglion neurons.J Neurophysiol. 2016 Mar;115(3):1577-86. doi: 10.1152/jn.00980.2015. Epub 2016 Feb 3. J Neurophysiol. 2016. PMID: 26843606 Free PMC article.
-
Protease-activated receptor 2 activation inhibits N-type Ca2+ currents in rat peripheral sympathetic neurons.Mol Cells. 2014 Nov;37(11):804-11. doi: 10.14348/molcells.2014.0167. Epub 2014 Nov 10. Mol Cells. 2014. PMID: 25410909 Free PMC article.
References
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Miscellaneous