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. 1989 Jul;414:283–300. doi: 10.1113/jphysiol.1989.sp017688

Post-natal development of K+ currents studied in isolated rat pineal cells.

L G Aguayo 1
PMCID: PMC1189142  PMID: 2607433

Abstract

1. The voltage-activated outward currents in diencephalon-derived neuroendocrine pineal cells, dissociated from rats aged 1 day to 3 weeks post-natal, were studied with the whole-cell variation of the patch-clamp technique and compared with those of adult rats (1-3 months post-natal). 2. Thirty-five per cent of the 1-week-old cells displayed a single slowly inactivating outward current that had properties which distinguished it from the classical IA and IK currents. This current, named IK(d) for developmental, activated at potentials near -35 mV. Its time to half-maximal activation (t 1/2) ranged from 16 ms at -30 mV to 4 ms at + 15 mV. No other membrane currents were apparent with depolarizing steps up to +80 mV. 3. IK(d) displayed slow inactivation at depolarized potentials. The time constant for this inactivation was on the order of several hundred milliseconds. The curve for steady-state inactivation disclosed that the current was 50% inactivated near -90 mV. This current was not found in cells dissociated from animals 4 or more weeks of age. 4. The reversal potential determined from the amplitude of the tail current at various repolarizing voltages was -76 mV. Tetraethylammonium and 4-aminopyridine reduced the amplitude of the current. The amplitude and time course of this current was not affected by the removal of external Ca2+. Similarly, removal of Cl- did not affect the current characteristics. 5. Sixty-five per cent of the 1-week-old cells displayed IA and IK. IK rose slowly with time and displayed a threshold of activation near -20 mV. No current decay was observed during a 160 ms pulse. IA activated with step potentials positive to -50 mV. This current rose faster than IK(d) and IK, and it had a significant decay over a 160 ms pulse. 6. IA and IK were observed as early as 1 day after birth. Comparison of the time course of activation of IA and IK from young and adult animals showed a small increase (2-3 ms at 0 mV) in the time to peak and half-maximal current, respectively. With a step potential to -20 mV, the time constant of decay of IA increased from 34.6 ms in 2-day-old animals to 42.9 ms in adult animals. 7. The results indicate that unlike adult pineal cells, some cells from young animals express a kinetically distinct outward current (IK(d)) which was observed in the absence of IA and IK.(ABSTRACT TRUNCATED AT 400 WORDS)

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Selected References

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  1. Aguayo L. G., Weight F. F. Characterization of membrane currents in dissociated adult rat pineal cells. J Physiol. 1988 Nov;405:397–419. doi: 10.1113/jphysiol.1988.sp017339. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Altar A. Development of the mammalian pineal gland. Dev Neurosci. 1982 Mar-Jun;5(2-3):166–180. doi: 10.1159/000112673. [DOI] [PubMed] [Google Scholar]
  3. Barish M. E. Differentiation of voltage-gated potassium current and modulation of excitability in cultured amphibian spinal neurones. J Physiol. 1986 Jun;375:229–250. doi: 10.1113/jphysiol.1986.sp016114. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Belluzzi O., Sacchi O., Wanke E. A fast transient outward current in the rat sympathetic neurone studied under voltage-clamp conditions. J Physiol. 1985 Jan;358:91–108. doi: 10.1113/jphysiol.1985.sp015542. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. 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]
  6. Brenner H. R., Lømo T., Williamson R. Control of end-plate channel properties by neurotrophic effects and by muscle activity in rat. J Physiol. 1987 Jul;388:367–381. doi: 10.1113/jphysiol.1987.sp016619. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cahalan M. D., Chandy K. G., DeCoursey T. E., Gupta S. A voltage-gated potassium channel in human T lymphocytes. J Physiol. 1985 Jan;358:197–237. doi: 10.1113/jphysiol.1985.sp015548. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Calvo J., Boya J. Postnatal development of cell types in the rat pineal gland. J Anat. 1983 Aug;137(Pt 1):185–195. [PMC free article] [PubMed] [Google Scholar]
  9. Cobbett P., Ingram C. D., Mason W. T. Sodium and potassium currents involved in action potential propagation in normal bovine lactotrophs. J Physiol. 1987 Nov;392:273–299. doi: 10.1113/jphysiol.1987.sp016780. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Connor J. A., Stevens C. F. Voltage clamp studies of a transient outward membrane current in gastropod neural somata. J Physiol. 1971 Feb;213(1):21–30. doi: 10.1113/jphysiol.1971.sp009365. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Cota G., Armstrong C. M. Potassium channel "inactivation" induced by soft-glass patch pipettes. Biophys J. 1988 Jan;53(1):107–109. doi: 10.1016/S0006-3495(88)83071-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. DeCoursey T. E., Chandy K. G., Gupta S., Cahalan M. D. Voltage-gated K+ channels in human T lymphocytes: a role in mitogenesis? Nature. 1984 Feb 2;307(5950):465–468. doi: 10.1038/307465a0. [DOI] [PubMed] [Google Scholar]
  13. Gonoi T., Hasegawa S. Post-natal disappearance of transient calcium channels in mouse skeletal muscle: effects of denervation and culture. J Physiol. 1988 Jul;401:617–637. doi: 10.1113/jphysiol.1988.sp017183. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Hamill O. P., Marty A., Neher E., Sakmann B., Sigworth F. J. Improved patch-clamp techniques for high-resolution current recording from cells and cell-free membrane patches. Pflugers Arch. 1981 Aug;391(2):85–100. doi: 10.1007/BF00656997. [DOI] [PubMed] [Google Scholar]
  15. Lindau M., Neher E. Patch-clamp techniques for time-resolved capacitance measurements in single cells. Pflugers Arch. 1988 Feb;411(2):137–146. doi: 10.1007/BF00582306. [DOI] [PubMed] [Google Scholar]
  16. Lingle C. J., Sombati S., Freeman M. E. Membrane currents in identified lactotrophs of rat anterior pituitary. J Neurosci. 1986 Oct;6(10):2995–3005. doi: 10.1523/JNEUROSCI.06-10-02995.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Marchetti C., Premont R. T., Brown A. M. A whole-cell and single-channel study of the voltage-dependent outward potassium current in avian hepatocytes. J Gen Physiol. 1988 Feb;91(2):255–274. doi: 10.1085/jgp.91.2.255. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Marrion N. V., Smart T. G., Brown D. A. Membrane currents in adult rat superior cervical ganglia in dissociated tissue culture. Neurosci Lett. 1987 Jun 1;77(1):55–60. doi: 10.1016/0304-3940(87)90606-9. [DOI] [PubMed] [Google Scholar]
  19. Matteson D. R., Deutsch C. K channels in T lymphocytes: a patch clamp study using monoclonal antibody adhesion. Nature. 1984 Feb 2;307(5950):468–471. doi: 10.1038/307468a0. [DOI] [PubMed] [Google Scholar]
  20. Nerbonne J. M., Gurney A. M., Rayburn H. B. Development of the fast, transient outward K+ current in embryonic sympathetic neurones. Brain Res. 1986 Jul 16;378(1):197–202. doi: 10.1016/0006-8993(86)90306-9. [DOI] [PubMed] [Google Scholar]
  21. Numann R. E., Wadman W. J., Wong R. K. Outward currents of single hippocampal cells obtained from the adult guinea-pig. J Physiol. 1987 Dec;393:331–353. doi: 10.1113/jphysiol.1987.sp016826. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. O'Dowd D. K., Ribera A. B., Spitzer N. C. Development of voltage-dependent calcium, sodium, and potassium currents in Xenopus spinal neurons. J Neurosci. 1988 Mar;8(3):792–805. doi: 10.1523/JNEUROSCI.08-03-00792.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Parfitt A., Weller J. L., Klein D. C., Sakai K. K., Marks B. H. Blockade by ouabain or elevated potassium ion concentration of the adrenergic and adenosine cyclic 3',5'-monophosphate-induced stimulation of pineal serotonin N-acetyltransferase activity. Mol Pharmacol. 1975 May;11(3):241–255. [PubMed] [Google Scholar]
  24. QUAY W. B., LEVINE B. E. Pineal growth and mitotic activity in the rat and the effects of colchicine and sex hormones. Anat Rec. 1957 Sep;129(1):65–77. doi: 10.1002/ar.1091290106. [DOI] [PubMed] [Google Scholar]
  25. Solc C. K., Aldrich R. W. Voltage-gated potassium channels in larval CNS neurons of Drosophila. J Neurosci. 1988 Jul;8(7):2556–2570. doi: 10.1523/JNEUROSCI.08-07-02556.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Storm J. F. Temporal integration by a slowly inactivating K+ current in hippocampal neurons. Nature. 1988 Nov 24;336(6197):379–381. doi: 10.1038/336379a0. [DOI] [PubMed] [Google Scholar]
  27. Tapp E., Blumfield M. The parenchymal cells of the rat pineal gland. Acta Morphol Neerl Scand. 1970 Nov;8(2):119–131. [PubMed] [Google Scholar]
  28. Yaari Y., Hamon B., Lux H. D. Development of two types of calcium channels in cultured mammalian hippocampal neurons. Science. 1987 Feb 6;235(4789):680–682. doi: 10.1126/science.2433765. [DOI] [PubMed] [Google Scholar]
  29. Yool A. J., Dionne V. E., Gruol D. L. Developmental changes in K+-selective channel activity during differentiation of the Purkinje neuron in culture. J Neurosci. 1988 Jun;8(6):1971–1980. doi: 10.1523/JNEUROSCI.08-06-01971.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]

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