|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Received July 9, 2002
Accepted after revision September 26, 2002
1 Division of Neuroscience and Psychological Medicine, Department of Neuromuscular Diseases, Imperial College London, Fulham Palace Road, London W6 8RF, UK
* To whom correspondence should be addressed. E-mail: r.navarrete{at}ic.ac.uk.
Neonatal rat motoneurones are electrically coupled via gap junctions and the incidence of this coupling declines during postnatal development. The mechanisms involved in this developmental regulation of gap junctional communication are largely unknown. Here we have studied the role of NMDA receptor-mediated glutamatergic synaptic activity in the regulation of motoneurone coupling. Gap junctional coupling was demonstrated by the presence of graded, short latency depolarising potentials following ventral root stimulation, and by the transfer of the low molecular weight tracer Neurobiotin to neighbouring motoneurones. Sites of close apposition between the somata and/or dendrites of the dye-coupled motoneurones were identified as potential sites of gap junctional coupling. Early postnatal blockade of the NMDA subtype of glutamate receptors using the non-competitive antagonist dizocilpine maleate (MK801) arrested the developmental decrease in electrotonic and dye coupling during the first postnatal week. These results suggest that the postnatal increase in glutamatergic synaptic activity associated with the onset of locomotion promote the loss of gap junctional connections between developing motoneurones.
This article has been cited by other articles:
![]() |
K. E. Personius, J. L. Karnes, and S. D. Parker NMDA Receptor Blockade Maintains Correlated Motor Neuron Firing and Delays Synapse Competition at Developing Neuromuscular Junctions J. Neurosci., September 3, 2008; 28(36): 8983 - 8992. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Quinlan and J. T. Buchanan Cellular and Synaptic Actions of Acetylcholine in the Lamprey Spinal Cord J Neurophysiol, August 1, 2008; 100(2): 1020 - 1031. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. E. Personius, Q. Chang, G. Z. Mentis, M. J. O'Donovan, and R. J. Balice-Gordon Reduced gap junctional coupling leads to uncorrelated motor neuron firing and precocious neuromuscular synapse elimination PNAS, July 10, 2007; 104(28): 11808 - 11813. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. O. Martin, G. Alonso, and N. C. Guerineau Agrin mediates a rapid switch from electrical coupling to chemical neurotransmission during synaptogenesis J. Cell Biol., May 9, 2005; 169(3): 503 - 514. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. M. Szabo, D. S. Faber, and M. J. Zoran Transient Electrical Coupling Delays the Onset of Chemical Neurotransmission at Developing Synapses J. Neurosci., January 7, 2004; 24(1): 112 - 120. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. O. Martin, M.-N. Mathieu, and N. C. Guerineau Evidence for Long-Lasting Cholinergic Control of Gap Junctional Communication between Adrenal Chromaffin Cells J. Neurosci., May 1, 2003; 23(9): 3669 - 3678. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M. Pastor, G. Z. Mentis, R. R. De la Cruz, E. Diaz, and R. Navarrete Increased Electrotonic Coupling in Spinal Motoneurons After Transient Botulinum Neurotoxin Paralysis in the Neonatal Rat J Neurophysiol, February 1, 2003; 89(2): 793 - 805. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |