Document Detail


Motor units within the normal rat medial gastrocnemius.
MedLine Citation:
PMID:  8329209     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The contractile properties, fatiguability and axonal conduction velocity were determined for 118 motor units in the medial gastrocnemius of eighteen rats. Fast-twitch and slow-twitch units could be categorized on the basis of the 'sag' test. For the purposes of statistical comparison the fast-twitch units were classified on the basis of their fatiguability as fast-fatiguable (FF), fast intermediate (FI) and fast fatigue-resistant (FR). As such, FR units tended to have a longer isometric twitch time course than other fast-twitch units. On the basis of peak tetanic force FF units were largest (mean 341 +/- 120 mN) followed by FI (145 +/- 85 mN), FR (87.3 +/- 38) and slow units (40.4 +/- 11.0 mN). There were no differences in motor axonal conduction velocity. Although units were categorized, it is clear that for all characteristics investigated the fast-twitch units exist as a continuum. Some of the largest FF units (peak force 350-500 mN) failed to maintain force with high-frequency stimulation (300 Hz) and this was associated with a failure of the EMG signal.
Authors:
L J Einsiedel; A R Luff
Related Documents :
23209729 - Stability of adult emergence and activity/rest rhythms in fruit flies drosophila melano...
11764319 - Type iii units in the gerbil dorsal cochlear nucleus may be spectral notch detectors.
20081849 - Ultrafast optogenetic control.
22036549 - Kinematic analysis of dynamic shoulder motion in patients with reverse total shoulder a...
21802039 - Quadricep and hamstring activation during drop jumps with changes in drop height.
3585459 - The representation of stimulus azimuth by high best-frequency azimuth-selective neurons...
998209 - Drill-generated noise levels in ear surgery.
15237839 - Sensitivity to interaural intensitive disparities: listeners' use of potential cues.
17550319 - Typing of amyloidosis in renal biopsies: diagnostic pitfalls.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Experimental physiology     Volume:  78     ISSN:  0958-0670     ISO Abbreviation:  Exp. Physiol.     Publication Date:  1993 May 
Date Detail:
Created Date:  1993-08-19     Completed Date:  1993-08-19     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  9002940     Medline TA:  Exp Physiol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  371-81     Citation Subset:  IM    
Affiliation:
Department of Physiology, Monash University, Clayton, Victoria, Australia.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Electric Stimulation
Femur
Knee
Male
Motor Neurons / physiology,  ultrastructure*
Muscle Contraction / physiology
Muscles / innervation*,  physiology
Neural Conduction / physiology
Rats
Rats, Sprague-Dawley
Time Factors

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


Previous Document:  Administration of 3,5,3'-triiodothyronine induces a rapid increase in enterocyte lactase-phlorizin h...
Next Document:  Mechanism of pregnancy-induced attenuation of contraction to phenylephrine in rat aorta.