Distinct receptors underlie glutamatergic signalling in inspiratory rhythm-generating networks and motor output pathways in neonatal rat

Ireland, M. F., Lenal, F. C., Lorier, A. R., Loomes, D. E., Adachi, T., Alvares, T. S., Greer, J. J. and Funk, G. D. (2008) Distinct receptors underlie glutamatergic signalling in inspiratory rhythm-generating networks and motor output pathways in neonatal rat. Journal of Physiology, 586 9: 2357-2370. doi:10.1113/jphysiol.2007.150532


Author Ireland, M. F.
Lenal, F. C.
Lorier, A. R.
Loomes, D. E.
Adachi, T.
Alvares, T. S.
Greer, J. J.
Funk, G. D.
Title Distinct receptors underlie glutamatergic signalling in inspiratory rhythm-generating networks and motor output pathways in neonatal rat
Journal name Journal of Physiology   Check publisher's open access policy
ISSN 0022-3751
Publication date 2008
Sub-type Article (original research)
DOI 10.1113/jphysiol.2007.150532
Volume 586
Issue 9
Start page 2357
End page 2370
Total pages 14
Place of publication Oxford
Publisher Blackwell for the Physiological Society
Language eng
Subject 11 Medical and Health Sciences
1103 Clinical Sciences
Abstract Despite the enormous diversity of glutamate (Glu) receptors and advances in understanding recombinant receptors, native Glu receptors underlying functionally identified inputs in active systems are poorly defined in comparison. In the present study we use UBP-302, which antagonizes GluR5 subunit-containing kainate (KA) receptors at ≤ 10 μm, but other KA and AMPA receptors at ≥ 100 μm, and rhythmically active in vitro preparations of neonatal rat to explore the contribution of non-NMDA receptor signalling in rhythm-generating and motor output compartments of the inspiratory network. At 10 μm, UBP-302 had no effect on inspiratory burst frequency or amplitude. At 100 μm, burst amplitude recorded from XII, C1 and C4 nerve roots was significantly reduced, but frequency was unaffected. The lack of a frequency effect was confirmed when local application of UBP-302 (100 μm) into the pre-Bötzinger complex (preBötC) did not affect frequency but substance P evoked a 2-fold increase. A UBP-302-sensitive (10 μm), ATPA-evoked frequency increase, however, established that preBötC networks are sensitive to GluR5 activation. Whole-cell recordings demonstrated that XII motoneurons also express functional GluR5-containing KA receptors that do not contribute to inspiratory drive, and confirmed the dose dependence of UBP-302 actions on KA and AMPA receptors. Our data provide the first evidence that the non-NMDA (most probably AMPA) receptors mediating glutamatergic transmission within preBötC inspiratory rhythm-generating networks are pharmacologically distinct from those transmitting drive to inspiratory motoneurons. This differential expression may ultimately be exploited pharmacologically to separately counteract depression of central respiratory rhythmogenesis or manipulate the drive to motoneurons controlling airway and pump musculature.
Keyword Glutamate
Neonatal Rats
In Vitro
Motoneurons Controlling
Airway
Pump Musculature
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
Queensland Brain Institute Publications
 
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Created: Fri, 11 Dec 2009, 14:45:27 EST by Ms May Balasaize on behalf of Queensland Brain Institute