Document Detail

Motor activity affects dopaminergic and noradrenergic systems of the dorsal horn of the rat lumbar spinal cord.
MedLine Citation:
PMID:  21538552     Owner:  NLM     Status:  MEDLINE    
Dopamine (DA) and noradrenaline (NA) modulate responses to nociceptive stimuli, within the dorsal horn of the spinal cord. Both neurotransmitters may play a role in supraspinal regulation in response to proprioceptive afferences to the dorsal horn. However, direct evidence of changes in neurotransmitter release within the dorsal horn due to non-noxious stimuli is lacking. The present study was designed to determine, whether non-nociceptive exercise produces changes in release of DA and NA within the dorsal horn, and whether these changes are associated with long-lasting inhibition after the exercise stops. Microdialysis probes, implanted in layers 2-5 of Rexed, in combination with high-performance liquid chromatography coupled to electrochemical detection (HPLC-EC) were used to measure concentrations of DA and NA metabolite (MHPG) in lumbar spinal cords of rats. Microdialysate was sampled before, during, and after a treadmill exercise of one hour. Results indicate that DA and NA releases are inhibited during non-nociceptive motor activity. At rest, DA concentration was 204 ± 10.5 pg/10 μl and was significantly decreased during exercise to -11.4% (P ≤ 0.05). Greater decrease occurred after 30 min of exercise and was of -31.4% (P ≤ 0.05). Similarly, MHPG was significantly decreased of -18% during exercise (P ≤ 0.05). When exercise stopped, both systems showed long-lasting inhibition. Exercise post-release lasted 30 min for DA and 90 min for MHPG. MHPG greatest decrease of -47.8% occurred 30 min after stopping the exercise (P ≤ 0.001). Thus, DA and NA systems seem to respond to exercise-induced proprioceptive afferent stimuli to the dorsal horn.
Christine G Gerin; Kristin Smith; Seritta Hill; Angela Hill; Ikenna C Madueke
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural    
Journal Detail:
Title:  Synapse (New York, N.Y.)     Volume:  65     ISSN:  1098-2396     ISO Abbreviation:  Synapse     Publication Date:  2011 Dec 
Date Detail:
Created Date:  2011-10-12     Completed Date:  2012-07-30     Revised Date:  2014-09-20    
Medline Journal Info:
Nlm Unique ID:  8806914     Medline TA:  Synapse     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1282-8     Citation Subset:  IM    
Copyright Information:
Copyright © 2011 Wiley-Liss, Inc.
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MeSH Terms
Dopamine / metabolism,  secretion*
Motor Activity / physiology*
Neural Inhibition / physiology
Neural Pathways / physiology,  secretion
Norepinephrine / metabolism,  secretion*
Posterior Horn Cells / physiology*
Presynaptic Terminals / metabolism,  secretion*
Rats, Sprague-Dawley
Grant Support
Reg. No./Substance:
VTD58H1Z2X/Dopamine; X4W3ENH1CV/Norepinephrine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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