 |
 Previous Article | Next Article 
The Journal of Neuroscience, July 1, 2000, 20(13):4855-4863
Excitatory Role of the Hyperpolarization-Activated Inward Current
in Phasic and Tonic Firing of Rat Supraoptic Neurons
Masoud
Ghamari-Langroudi and
Charles
W.
Bourque
Centre for Research in Neuroscience, Montreal General Hospital and
McGill University, Montreal, Quebec H3G 1A4, Canada
The properties and functional roles of the
hyperpolarization-activated inward current
(IH) in magnocellular neurosecretory cells (MNCs) were investigated during sharp microelectrode recordings from supraoptic neurons in superfused explants of rat hypothalamus. Under current clamp, voltage responses to hyperpolarizing current pulses featured depolarizing sags that were abolished by the
IH blocker ZD 7288. Under voltage clamp,
subtraction of current responses to hyperpolarizing steps recorded in
the absence and presence of ZD 7288 was used to investigate the
properties of IH. Current-voltage analysis
revealed that steady-state IH amplitude
increases with hyperpolarization, with half-maximal activation of the
underlying conductance occurring at  78 mV. The time course of
activation of IH during hyperpolarizing
steps was monoexponential with time constants (100-800 msec)
decreasing with hyperpolarization. The effects of ZD 7288 on
IH were slow ( , ~15 min), irreversible, and half-maximal at 1.8 µM. When tested on continuously
active MNCs, application of 30-60 µM ZD 7288 caused a
significant reduction in firing rate. In phasically active MNCs, the
drug decreased burst duration and intraburst firing frequency and
caused an increase in the duration of interburst intervals. These
effects were accompanied with a small hyperpolarization of the membrane
potential. In contrast, ZD 7288 had no effect on spike duration, on the
amplitude of calcium-dependent afterpotentials, or on the frequencies
and amplitudes of spontaneous synaptic potentials. These results
confirm the presence of IH in MNCs of the
rat supraoptic nucleus and suggest that the presence of this
conductance provides an excitatory drive that contributes to phasic and
tonic firing.
Key words:
vasopressin; oxytocin; neurohypophysis; neurosecretory
cell; burst firing; hypothalamus; ZD 7288
Copyright © 2000 Society for Neuroscience 0270-6474/00/20134855-09$05.00/0
This article has been cited by other articles:
|
|
|
|
 
V. Scott, V. R. Bishop, G. Leng, and C. H. Brown
Dehydration-induced modulation of \#954;-opioid inhibition of vasopressin neurone activity
J. Physiol.,
December 1, 2009;
587(23):
5679 - 5689.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. Zhang, M. A. Bosch, E. A. Rick, M. J. Kelly, and O. K. Ronnekleiv
17{beta}-Estradiol Regulation of T-Type Calcium Channels in Gonadotropin-Releasing Hormone Neurons
J. Neurosci.,
August 26, 2009;
29(34):
10552 - 10562.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Ruan and C. H. Brown
Feedback inhibition of action potential discharge by endogenous adenosine enhancement of the medium afterhyperpolarization
J. Physiol.,
March 1, 2009;
587(5):
1043 - 1056.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J.-M. Israel, D. A. Poulain, and S. H. R. Oliet
Oxytocin-Induced Postinhibitory Rebound Firing Facilitates Bursting Activity in Oxytocin Neurons
J. Neurosci.,
January 9, 2008;
28(2):
385 - 394.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
A. Arroyo, B. Kim, R. L. Rasmusson, G. Bett, and J. Yeh
Hyperpolarization-Activated Cation Channels Are Expressed in Rat Hypothalamic Gonadotropin-Releasing Hormone (GnRH) Neurons and Immortalized GnRH Neurons
Reproductive Sciences,
September 1, 2006;
13(6):
442 - 450.
[Abstract]
[PDF]
|
|
|
|
|
|
|
T. J. E. Stachniak and C. W. Bourque
Visually guided whole cell patch clamp of mouse supraoptic nucleus neurons in cultured and acute conditions
Am J Physiol Regulatory Integrative Comp Physiol,
July 1, 2006;
291(1):
R68 - R76.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. H. Brown, G. Leng, M. Ludwig, and C. W. Bourque
Endogenous Activation of Supraoptic Nucleus {kappa}-Opioid Receptors Terminates Spontaneous Phasic Bursts in Rat Magnocellular Neurosecretory Cells
J Neurophysiol,
May 1, 2006;
95(5):
3235 - 3244.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D.-L. Qiu, C.-P. Chu, T. Shirasaka, H. Tsukino, H. Nakao, K. Kato, T. Kunitake, T. Katoh, and H. Kannan
Corticotrophin-Releasing Factor Augments the IH in Rat Hypothalamic Paraventricular Nucleus Parvocellular Neurons In Vitro
J Neurophysiol,
July 1, 2005;
94(1):
226 - 234.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
T. Adachi, D. M. Robinson, G. B. Miles, and G. D. Funk
Noradrenergic modulation of XII motoneuron inspiratory activity does not involve {alpha}2-receptor inhibition of the Ih current or presynaptic glutamate release
J Appl Physiol,
April 1, 2005;
98(4):
1297 - 1308.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Ghamari-Langroudi and C. W. Bourque
Muscarinic Receptor Modulation of Slow Afterhyperpolarization and Phasic Firing in Rat Supraoptic Nucleus Neurons
J. Neurosci.,
September 1, 2004;
24(35):
7718 - 7726.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
Y.-F. Wang and G. I. Hatton
Milk Ejection Burst-Like Electrical Activity Evoked in Supraoptic Oxytocin Neurons in Slices From Lactating Rats
J Neurophysiol,
May 1, 2004;
91(5):
2312 - 2321.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
R. M Slugg, S.-X. Zheng, Y. Fang, M. J Kelly, and O. K Ronnekleiv
Baclofen inhibits guinea pig magnocellular neurones via activation of an inwardly rectifying K+ conductance
J. Physiol.,
August 15, 2003;
551(1):
295 - 308.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Hirasawa, D. Mouginot, M. G. Kozoriz, S. B. Kombian, and Q. J. Pittman
Vasopressin Differentially Modulates Non-NMDA Receptors in Vasopressin and Oxytocin Neurons in the Supraoptic Nucleus
J. Neurosci.,
May 15, 2003;
23(10):
4270 - 4277.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Tanaka, N. Wu, C.-F. Hsaio, J. Turman Jr., and S. H. Chandler
Development of Inward Rectification and Control of Membrane Excitability in Mesencephalic V Neurons
J Neurophysiol,
March 1, 2003;
89(3):
1288 - 1298.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. R. Chaplan, H.-Q. Guo, D. H. Lee, L. Luo, C. Liu, C. Kuei, A. A. Velumian, M. P. Butler, S. M. Brown, and A. E. Dubin
Neuronal Hyperpolarization-Activated Pacemaker Channels Drive Neuropathic Pain
J. Neurosci.,
February 15, 2003;
23(4):
1169 - 1178.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Han, C. Gnatenco, C. D Sladek, and D. Kim
Background and tandem-pore potassium channels in magnocellular neurosecretory cells of the rat supraoptic nucleus
J. Physiol.,
February 1, 2003;
546(3):
625 - 639.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. L. Smith and T. S. Otis
Persistent Changes in Spontaneous Firing of Purkinje Neurons Triggered by the Nitric Oxide Signaling Cascade
J. Neurosci.,
January 15, 2003;
23(2):
367 - 372.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. R Williams, S. R Christensen, G. J Stuart, and M. Hausser
Membrane potential bistability is controlled by the hyperpolarization-activated current IH in rat cerebellar Purkinje neurons in vitro
J. Physiol.,
March 1, 2002;
539(2):
469 - 483.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Ghamari-Langroudi and C. W Bourque
Ionic basis of the caesium-induced depolarisation in rat supraoptic nucleus neurones
J. Physiol.,
November 1, 2001;
536(3):
797 - 808.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L.-N. Cui, E. Coderre, and L. P. Renaud
Glutamate and GABA mediate suprachiasmatic nucleus inputs to spinal-projecting paraventricular neurons
Am J Physiol Regulatory Integrative Comp Physiol,
October 1, 2001;
281(4):
R1283 - R1289.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
I. M. Raman, A. E. Gustafson, and D. Padgett
Ionic Currents and Spontaneous Firing in Neurons Isolated from the Cerebellar Nuclei
J. Neurosci.,
December 15, 2000;
20(24):
9004 - 9016.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. R Williams, S. R Christensen, G. J Stuart, and M. Hausser
Membrane potential bistability is controlled by the hyperpolarization-activated current IH in rat cerebellar Purkinje neurons in vitro
J. Physiol.,
March 1, 2002;
539(2):
469 - 483.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
