Switch to
| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
20
|
| pubmed:dateCreated |
1998-10-23
|
| pubmed:abstractText |
We tested the hypothesis that spinal plasticity elicited by chronic bilateral cervical dorsal rhizotomy (C3-C5; CDR) has functional implications for respiratory motor control. Surgery was performed on rats (CDR or sham-operated) 26 d before phrenic motoneurons were retrogradely labeled with cholera toxin. Rats were killed 2 d later, and their spinal cords were harvested and processed to reveal the cholera toxin-labeled phrenic motoneurons and serotonin-immunoreactive terminals. The number of serotonin-immunoreactive terminals within 5 micrometer of labeled phrenic motoneuron soma and primary dendrites increased 2.1-fold after CDR versus sham-operation. Time-dependent phrenic motor responses to hypoxia were compared among CDR, sham-operated, and control rats. Anesthetized, paralyzed, vagotomized, and artificially ventilated rats were exposed to three, 5 min episodes of isocapnic hypoxia (FiO2 = 0.11), separated by 5 min hyperoxic intervals (FiO2 = 0.5). One hour after hypoxia, a long-lasting, serotonin-dependent enhancement of phrenic motor output (long-term facilitation) was observed in both sham and control rats. After CDR, long-term facilitation was 108 and 163% greater than control and sham responses, respectively. Pretreatment of CDR rats with a 5-HT2 receptor antagonist (ketanserin tartrate, 2 mg/kg, i.v.) before episodic hypoxia prevented long-term facilitation and revealed a modest (-28 +/- 13%; p < 0.05) long-lasting depression of phrenic motor output. The results indicate that CDR: (1) increases serotonergic innervation of the phrenic motor nucleus; and (2) augments serotonin-dependent long-term facilitation of phrenic motor output. These results further suggest a form of plasticity based on changes in the capacity for neuromodulation.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Oct
|
| pubmed:issn |
0270-6474
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
15
|
| pubmed:volume |
18
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
8436-43
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:9763486-Action Potentials,
pubmed-meshheading:9763486-Animals,
pubmed-meshheading:9763486-Anoxia,
pubmed-meshheading:9763486-Cell Size,
pubmed-meshheading:9763486-Cholera Toxin,
pubmed-meshheading:9763486-Dendrites,
pubmed-meshheading:9763486-Male,
pubmed-meshheading:9763486-Motor Neurons,
pubmed-meshheading:9763486-Neuronal Plasticity,
pubmed-meshheading:9763486-Periodicity,
pubmed-meshheading:9763486-Phrenic Nerve,
pubmed-meshheading:9763486-Rats,
pubmed-meshheading:9763486-Rats, Sprague-Dawley,
pubmed-meshheading:9763486-Respiration,
pubmed-meshheading:9763486-Rhizotomy,
pubmed-meshheading:9763486-Serotonin
|
| pubmed:year |
1998
|
| pubmed:articleTitle |
Cervical dorsal rhizotomy enhances serotonergic innervation of phrenic motoneurons and serotonin-dependent long-term facilitation of respiratory motor output in rats.
|
| pubmed:affiliation |
Unité de Recherche en Pédiatrie, Centre Hôspitalier Universitaire de Québec, Pavillon St-François d'Assise, Québec, QC G1L 3L5 Canada.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|