The nucleus retroambiguus as possible site for inspiratory rhythm generation caudal to obex

Jones, Sarah E., Saad, Mona, Lewis, David I., Subramanian, Hari H. and Dutschmann, Mathias (2012) The nucleus retroambiguus as possible site for inspiratory rhythm generation caudal to obex. Respiratory Physiology and Neurobiology, 180 2-3: 305-310. doi:10.1016/j.resp.2011.12.007

Author Jones, Sarah E.
Saad, Mona
Lewis, David I.
Subramanian, Hari H.
Dutschmann, Mathias
Title The nucleus retroambiguus as possible site for inspiratory rhythm generation caudal to obex
Journal name Respiratory Physiology and Neurobiology   Check publisher's open access policy
ISSN 1569-9048
Publication date 2012-03
Year available 2012
Sub-type Article (original research)
DOI 10.1016/j.resp.2011.12.007
Volume 180
Issue 2-3
Start page 305
End page 310
Total pages 6
Place of publication Amsterdam, The Netherlands
Publisher Elsevier
Collection year 2013
Language eng
Formatted abstract
We investigated whether spinalized animals can produce inspiratory rhythm. We recorded spinal inspiratory phrenic (PNA) and cranial inspiratory hypoglossal (HNA) nerve activity in the perfused brainstem preparation of rat. Complete transverse transections were performed at 1.5 (pyramidal decussation) or 2. mm (first cervical spinal segment) caudal to obex. Excitatory drive was enhanced by either extracellular potassium, hypercapnia or by stimulating arterial chemoreceptors. Caudal transections immediately eliminated descending network drive for PNA, while the cranial inspiratory HNA remained unaffected. After transection, PNA bursting remained sporadic even during enhanced excitatory drive. This implies, cervical spinal circuits lack intrinsic rhythmogenic capacity. Rostral transections also abolished PNA immediately. However, HNA also progressively lost its amplitude and rhythm. Chemoreceptor activation only triggered tonic, non-rhythmic HNA. Thus the integrity of ponto-medullary circuitry was maintained. Our results suggest that an area overlapping the caudal nucleus retroambiguus provides critical ascending input to the ponto-medullary respiratory network for inspiratory rhythm generation.
Keyword Nucleus retroambiguus
Respiratory rhythm generation
Spinal cord
Respiratory Rhythm
Spinal Integration
Neuron Group
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Non-UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: UQ Centre for Clinical Research Publications
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Created: Tue, 01 Oct 2013, 14:40:53 EST by Hari Subramanian on behalf of UQ Centre for Clinical Research