JN Information on EB 2010
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Neurophysiol 80: 2710-2717, 1998;
0022-3077/98 $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 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 Google Scholar
Google Scholar
Right arrow Articles by Pennartz, C.M.A.
Right arrow Articles by Buijs, R. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pennartz, C.M.A.
Right arrow Articles by Buijs, R. M.

The Journal of Neurophysiology Vol. 80 No. 5 November 1998, pp. 2710-2717
Copyright ©1998 The American Physiological Society

Membrane Properties and Morphology of Vasopressin Neurons in Slices of Rat Suprachiasmatic Nucleus

C.M.A. Pennartz, N.P.A. Bos, M.T.G. De Jeu, A.M.S. Geurtsen, M. Mirmiran, A. A. Sluiter, and R. M. Buijs

Graduate School Neurosciences Amsterdam, Netherlands Institute for Brain Research, 1105 AZ Amsterdam, The Netherlands

Pennarts, C.M.A., N.P.A. Bos, M.T.G. De Jeu, A.M.S. Geurtsen, M. Mirmiran, A. A. Sluiter, and R. M. Buijs. Membrane properties and morphology of vasopressin neurons in slices of rat suprachiasmatic nucleus. J. Neurophysiol. 80: 2710-2717, 1998. Vasopressin (VP) neurons in the suprachiasmatic nucleus (SCN) are thought to be closely linked to neural mechanisms for circadian timekeeping. To gain insight into the cellular-physiological principles that govern spike-driven VP release and to examine whether VP cells can be electrophysiologically and morphologically identified by a unique combination of features, we recorded membrane properties by whole cell patch-clamp methods and stained the cells with biocytin. In current-clamp mode, VP neurons recorded during subjective daytime expressed a clear time-dependent inward rectification but no pronounced low-threshold Ca2+ potential after hyperpolarizing current pulses. Their spontaneous firing rate varied between 0.6 and 13.4 Hz and was generally tonic and irregular. Spike afterhyperpolarizations (AHPs) were steeply rising and monophasic. Spikes were preceded by depolarizing ramps mediated by a slow component of Na+ current. Spike trains evoked by depolarizing current pulses displayed frequency adaptation and were usually followed by an AHP lasting 0.5-2.0 s. Spontaneous postsynaptic potentials were present in a majority of cells. Voltage-clamp recordings revealed a Ba2+-sensitive K+ current that exerts a tonic, hyperpolarizing influence on the membrane potential. This set of membrane properties was not significantly different from other cells in the dorsomedial region and is characteristic for cluster I cells, which were described previously and are widely encountered throughout the SCN. None of the cells could be classified as belonging to cluster II or III, which were indeed found mainly outside the dorsomedial region. Morphologically, single VP neurons were characterized by compact, mono- or bipolar dendritic branching patterns and numerous varicosities throughout the dendrites. They generally possessed few axon collaterals, most of which remained inside the boundaries of the SCN but were occasionally seen to project to SCN target areas. In conclusion, VP neurons in the SCN express several active membrane poperties, including time-dependent inward rectification, frequency adaptation in spike trains, monophasic spike AHPs, and Ba2+-sensitive K+ current. VP release is proposed to be governed by tonic and irregular patterns of spontaneous firing. The electrophysiological and cytological properties of VP neurons are representative for a majority of SCN cells and define them as a subset of previously defined cluster I cells.




This article has been cited by other articles:


Home page
 J Biol RhythmsHome page
M. P. Butler and R. Silver
Basis of Robustness and Resilience in the Suprachiasmatic Nucleus: Individual Neurons Form Nodes in Circuits that Cycle Daily
J Biol Rhythms, October 1, 2009; 24(5): 340 - 352.
[Abstract] [PDF]

Home page
 Cold Spring Harb Symp Quant BiolHome page
L. Yan, I. Karatsoreos, J. LeSauter, D. K. Welsh, S. Kay, D. Foley, and R. Silver
Exploring Spatiotemporal Organization of SCN Circuits
Cold Spring Harb Symp Quant Biol, January 1, 2007; 72(0): 527 - 541.
[Abstract] [PDF]

Home page
 J. Neurosci.Home page
A. C. Jackson, G. L. Yao, and B. P. Bean
Mechanism of Spontaneous Firing in Dorsomedial Suprachiasmatic Nucleus Neurons
J. Neurosci., September 15, 2004; 24(37): 7985 - 7998.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
M. de Jeu, A. Geurtsen, and C. Pennartz
A Ba2+-Sensitive K+ Current Contributes to the Resting Membrane Potential of Neurons in Rat Suprachiasmatic Nucleus
J Neurophysiol, August 1, 2002; 88(2): 869 - 878.
[Abstract] [Full Text] [PDF]

Home page
 J. Neurophysiol.Home page
M. De Jeu and C. Pennartz
Circadian Modulation of GABA Function in the Rat Suprachiasmatic Nucleus: Excitatory Effects During the Night Phase
J Neurophysiol, February 1, 2002; 87(2): 834 - 844.
[Abstract] [Full Text] [PDF]


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