| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Institute of Physiology, University of Bern, Bern, Switzerland
* To whom correspondence should be addressed. E-mail: darbon{at}pyl.unibe.ch.
Disinhibition-induced bursting activity in cultures of fetal rat spinal cord is mainly controlled by intrinsic spiking with subsequent recurrent excitation of the network through glutamate synaptic transmission, and by auto-regulation of neuronal excitability. Here we investigated the contribution of the electrogenic Na/K pump to the auto-regulation of excitability using extracellular recordings by multielectrode arrays (MEAs) and intracellular whole-cell recordings from spinal interneurons. The blockade of the electrogenic Na/K pump by strophanthidin led to an immediate and transient increase in the burst rate together with an increase in the asynchronous background activity. Later, the burst rate decreased to initial values and the bursts became shorter and smaller. In single neurons, we observed an immediate depolarization of the membrane during the interburst intervals concomitant with the rise in burst rate. This depolarization was more pronounced during disinhibition than during control, suggesting that the pump was more active. Later a decrease in burst rate was observed and, in some neurons, a complete cessation of firing. Most of the effects of strophanthidin could be reproduced by high K+-induced depolarization. During prolonged current injections, spinal interneurons exhibited spike frequency adaptation, which remained unaffected by strophanthidin. These results suggest that the electrogenic Na/K pump is responsible for the hyperpolarization and thus for the changes in excitability during the interburst intervals, however, not for the spike frequency adaptation during the bursts.
This article has been cited by other articles:
|
|
 |
|
  S. Tazerart, L. Vinay, and F. Brocard The Persistent Sodium Current Generates Pacemaker Activities in the Central Pattern Generator for Locomotion and Regulates the Locomotor Rhythm J. Neurosci., August 20, 2008; 28(34): 8577 - 8589. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Yvon, A. Czarnecki, and J. Streit Riluzole-Induced Oscillations in Spinal Networks J Neurophysiol, May 1, 2007; 97(5): 3607 - 3620. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y.-F. Wang and G. I. Hatton Dominant Role of {beta}{gamma} Subunits of G-Proteins in Oxytocin-Evoked Burst Firing J. Neurosci., February 21, 2007; 27(8): 1902 - 1912. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Furlan, G. Taccola, M. Grandolfo, L. Guasti, A. Arcangeli, A. Nistri, and L. Ballerini ERG Conductance Expression Modulates the Excitability of Ventral Horn GABAergic Interneurons That Control Rhythmic Oscillations in the Developing Mouse Spinal Cord J. Neurosci., January 24, 2007; 27(4): 919 - 928. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Brocard, D. Verdier, I. Arsenault, J. P. Lund, and A. Kolta Emergence of Intrinsic Bursting in Trigeminal Sensory Neurons Parallels the Acquisition of Mastication in Weanling Rats J Neurophysiol, November 1, 2006; 96(5): 2410 - 2424. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y.-C. Wang and R.-C. Huang Effects of Sodium Pump Activity on Spontaneous Firing in Neurons of the Rat Suprachiasmatic Nucleus J Neurophysiol, July 1, 2006; 96(1): 109 - 118. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Cangiano and S. Grillner Mechanisms of Rhythm Generation in a Spinal Locomotor Network Deprived of Crossed Connections: The Lamprey Hemicord J. Neurosci., January 26, 2005; 25(4): 923 - 935. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. Del Negro, C. Morgado-Valle, J. A. Hayes, D. D. Mackay, R. W. Pace, E. A. Crowder, and J. L. Feldman Sodium and Calcium Current-Mediated Pacemaker Neurons and Respiratory Rhythm Generation J. Neurosci., January 12, 2005; 25(2): 446 - 453. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. K. Kosmidis, O. Pierrefiche, and J.-F. Vibert Respiratory-Like Rhythmic Activity Can Be Produced by an Excitatory Network of Non-Pacemaker Neuron Models J Neurophysiol, August 1, 2004; 92(2): 686 - 699. [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]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
