JN Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Neurophysiol 84: 2767-2776, 2000;
0022-3077/00 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via ISI Web of Science (18)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Cameron, J. S.
Right arrow Articles by Dryer, S. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Cameron, J. S.
Right arrow Articles by Dryer, S. E.

The Journal of Neurophysiology Vol. 84 No. 6 December 2000, pp. 2767-2776
Copyright ©2000 by the American Physiological Society

BK-Type KCa Channels in Two Parasympathetic Cell Types: Differences in Kinetic Properties and Developmental Expression

Jill S. Cameron and Stuart E. Dryer

Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204-5513

Cameron, Jill S. and Stuart E. Dryer. BK-Type KCa Channels in Two Parasympathetic Cell Types: Differences in Kinetic Properties and Developmental Expression. J. Neurophysiol. 84: 2767-2776, 2000. The intrinsic electrical properties of identified choroid and ciliary neurons of the chick ciliary ganglion were examined by patch-clamp recording methods. These neurons are derived from a common pool of mesencephalic neural crest precursor cells but innervate different target tissues and have markedly different action potential waveforms and intrinsic patterns of repetitive spike discharge. Therefore it is important to determine whether these cell types express different types of plasma membrane ionic channels, and to ascertain the developmental stages at which these cell types begin to diverge. This study has focused on large-conductance Ca2+-activated K+ channels (KCa), which are known to regulate spike waveform and repetitive firing in many cell types. Both ciliary ganglion cell types, identified on the basis of size and somatostatin immunoreactivity, express a robust macroscopic KCa carried by a kinetically homogeneous population of large-conductance (BK-type) KCa channels. However, the kinetic properties of these channels are different in the two cell types. Steady-state fluctuation analyses of macroscopic KCa produced power spectra that could be fitted with a single Lorentzian curve in both cell types. However, the resulting corner frequency was significantly lower in choroid neurons than in ciliary neurons, suggesting that the underlying KCa channels have a longer mean open-time in choroid neurons. Consistent with fluctuation analyses, significantly slower gating of KCa channels in choroid neurons was also observed during macroscopic activation and deactivation at membrane potentials positive to -30 mV. Differences in the kinetic properties of KCa channels could also be observed directly in single-channel recordings from identified embryonic day 13 choroid and ciliary neurons. The mean open-time of large-conductance KCa channels was significantly greater in choroid neurons than in ciliary neurons in excised inside-out patches. The developmental expression of functional KCa channels appears to be regulated differently in the two cell types. Although both cell types acquire functional KCa at the same developmental stages (embryonic days 9-13), functional expression of these channels in ciliary neurons requires target-derived trophic factors. In contrast, expression of functional KCa channels proceeds normally in choroid neurons developing in vitro in the absence of target-derived trophic factors. Consistent with this, extracts of ciliary neuron target tissues (striated muscle of the iris/ciliary body) contain KCa stimulatory activity. However, KCa stimulatory activity cannot be detected in extracts of the smooth muscle targets of choroid neurons.




This article has been cited by other articles:


Home page
 Am. J. Physiol. Renal Physiol.Home page
E. Y. Kim, K.-J. Choi, and S. E. Dryer
Nephrin binds to the COOH terminus of a large-conductance Ca2+-activated K+ channel isoform and regulates its expression on the cell surface
Am J Physiol Renal Physiol, July 1, 2008; 295(1): F235 - F246.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
S. Zou, S. Jha, E. Y. Kim, and S. E. Dryer
The {beta}1 Subunit of L-Type Voltage-Gated Ca2+ Channels Independently Binds to and Inhibits the Gating of Large-Conductance Ca2+-Activated K+ Channels
Mol. Pharmacol., February 1, 2008; 73(2): 369 - 378.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
E. Y. Kim, S. Zou, L. D. Ridgway, and S. E. Dryer
beta1-Subunits Increase Surface Expression of a Large-Conductance Ca2+-Activated K+ Channel Isoform
J Neurophysiol, May 1, 2007; 97(5): 3508 - 3516.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
M. E. Werner, A.-M. Knorn, A. L. Meredith, R. W. Aldrich, and M. T. Nelson
Frequency encoding of cholinergic- and purinergic-mediated signaling to mouse urinary bladder smooth muscle: modulation by BK channels
Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2007; 292(1): R616 - R624.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
K. Rimmer and A. A. Harper
Developmental Changes in Electrophysiological Properties and Synaptic Transmission in Rat Intracardiac Ganglion Neurons
J Neurophysiol, June 1, 2006; 95(6): 3543 - 3552.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Renal Physiol.Home page
K. S. Thorneloe, A. L. Meredith, A. M. Knorn, R. W. Aldrich, and M. T. Nelson
Urodynamic properties and neurotransmitter dependence of urinary bladder contractility in the BK channel deletion model of overactive bladder
Am J Physiol Renal Physiol, September 1, 2005; 289(3): F604 - F610.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
G. M. Herrera, B. Etherton, B. Nausch, and M. T. Nelson
Negative feedback regulation of nerve-mediated contractions by KCa channels in mouse urinary bladder smooth muscle
Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2005; 289(2): R402 - R409.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
P. V. Lovell, J. T. King, and D. P. McCobb
Acute Modulation of Adrenal Chromaffin Cell BK Channel Gating and Cell Excitability by Glucocorticoids
J Neurophysiol, January 1, 2004; 91(1): 561 - 570.
[Abstract] [Full Text]

Home page
 J. Neurosci.Home page
M. Martin-Caraballo and S. E. Dryer
Glial Cell Line-Derived Neurotrophic Factor and Target-Dependent Regulation of Large-Conductance KCa Channels in Developing Chick Lumbar Motoneurons
J. Neurosci., December 1, 2002; 22(23): 10201 - 10208.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurosci.Home page
M. Martin-Caraballo and S. E. Dryer
Activity- and Target-Dependent Regulation of Large-Conductance Ca2+-Activated K+ Channels in Developing Chick Lumbar Motoneurons
J. Neurosci., January 1, 2002; 22(1): 73 - 81.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
R. L. Anderson, P. Jobling, and I. L. Gibbins
Development of Electrophysiological and Morphological Diversity in Autonomic Neurons
J Neurophysiol, September 1, 2001; 86(3): 1237 - 1251.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online