Document Type
Article
Version
publisher_pdf
Publication Date
2014
Abstract
Glial cell line-derived neurotrophic factor (GDNF) may play a role in delaying
the onset of aging and help compress morbidity by preventing motor unit
degeneration. Exercise has been shown to alter GDNF expression differently in
slow- and fast-twitch myofibers. The aim was to examine the effects of different
intensities (10, 20, ~30, and ~40 m.min-1) of wheel running on GDNF expression
and neuromuscular junction (NMJ) plasticity in slow- and fast-twitch
myofibers. Male Sprague-Dawley Rats (4 weeks old) were divided into two
sedentary control groups (CON4 week, n = 5 and CON6 week, n = 5), two
involuntary running groups, one at a low velocity; 10 m/min (INVOL-low,
n = 5), and one at a higher velocity; 20 m/min (INVOL-high, n = 5), and two
voluntary running groups with resistance (VOL-R, n = 5, 120 g), and without
resistance (VOL-NR, n = 5, 4.5 g). GDNF protein content, determined by
enzyme-linked immunosorbent assay (ELISA), increased significantly in the
recruited muscles. Plantaris (PLA) GDNF protein content increased 174%
(P < 0.05) and 161% (P < 0.05) and end plate-stained area increased 123%
(P < 0.05) and 72% (P < 0.05) following VOL-R, and VOL-NR training,
respectively, when compared to age-matched controls. A relationship exists
between GDNF protein content and end plate area (r = 0.880, P < 0.01,
n = 15). VOL-R training also resulted in more dispersed synapses in the PLA
muscle when compared to age-matched controls (P < 0.05). Higher intensity
exercise (>30 m/min) can increase GDNF protein content in fast-twitch myofibers
as well as induce changes in the NMJ morphology. These findings help
to inform exercise prescription to preserve the integrity of the neuromuscular
system through aging and disease.
WMU ScholarWorks Citation
Gyorkos, Amy Morrison and Spitsbergen, John M., "GDNF Content and NMJ Morphology Are Altered in Recruited Muscles Following High-Speed and Resistance Wheel Training" (2014). Biological Sciences Faculty and Graduate Student Research. 5.
https://scholarworks.wmich.edu/biology_research/5
Published Citation
Gyorkos, Amy Morrison, and John M. Spitsbergen. "GDNF Content and NMJ Morphology are Altered in Recruited Muscles Following High-Speed and Resistance Wheel Training." Physiological reports 2.2 (2014)