Ventral motor neuron alterations in rat spinal cord after chronic exercise

Gilliam, Thomas B.; Roy, Raja; Taylor, J. F.; Heusner, William W.; Huss, Wayne D. Van

doi:10.1007/bf01946563

Cited by 15 publications

(7 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It should be noted, however, that some exercise studies have revealed adaptations in the soma size and oxidative capacity of motoneurons. A small but significant shift in the frequency distribution of soma size of an unspecified population of ventral horn neurons (located at L4–S2) toward smaller‐sized cells was reported in both sprint‐ and endurance‐trained rats compared to control rats 19. In contrast, Nakano et al36 reported a 14% increase in soma size of motoneurons in the soleus motoneuron pool, but no change in the extensor digitorum motoneuron pool, after 10 weeks of treadmill training (2 h/day, 30 m/min, 5 days/week).…”

Section: Discussionmentioning

confidence: 92%

Rat α‐ and γ‐motoneuron soma size and succinate dehydrogenase activity are independent of neuromuscular activity level

et al. 2007

View full text Add to dashboard Cite

The chronic level of neuromuscular activity, that is, activation and loading, strongly influences the morphological, metabolic, phenotypic, and physiological properties of skeletal muscles. The effects on the innervating motoneurons, however, are less established. We determined and compared the effects of 30 days of decreased activity (induced by a complete mid-thoracic spinal cord transection, ST) or near inactivity (induced by spinal cord isolation, SI) on the soma size and succinate dehydrogenase (SDH) activity of motoneurons innervating a predominantly slow ankle extensor (soleus) and a predominantly fast ankle flexor (tibialis anterior) muscle of adult rats. Soleus and tibialis anterior motoneuron pools were labeled retrogradely using nuclear yellow. The alpha- and gamma-motoneurons were classified based on soma size. Mean number of labeled motoneurons, and mean soma size and SDH activity for both alpha- and gamma-motoneurons were similar in control, ST, and SI rats. Compared to previous reports showing significant decreases in muscle fiber size and adaptations toward a "faster" metabolic profile following ST and SI, the results indicate that, unlike the muscles they innervate, the motoneurons are relatively unresponsive to chronic reductions in neuromuscular activity. The implication of these results is that mean size and SDH activity are independent of the number of action potentials generated by both alpha- and gamma-motoneurons and that even the absence of afferent input to the spinal cord has no influence on size and oxidative metabolic potential of the motoneuron soma.

show abstract

Section: Discussionmentioning

confidence: 92%

Rat α‐ and γ‐motoneuron soma size and succinate dehydrogenase activity are independent of neuromuscular activity level

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Since nerve axon diameter is very highly related to conduction velocity (3,28,41), any change in thameter would cause a concomitant change in conduction velocity. Histochemical changes in ventral motoneurons following long-term exercise have been observed (15,16), suggesting that there is indeed dynamic metabolic activity occurring in motoneurons following chronic exercise. The experiments conducted by Edgerton and his associates in spinalized cats showed that those animals who were exercised for 13-14 weeks following spinalization had faster nerve conduction velocities than those who were not exercised (11).…”

Section: Discussionmentioning

confidence: 99%

Ulnar and Posterior Tibial Nerve Conduction Velocity in Athletes

Kamen¹,

Taylor²,

Beehler³

1984

Int J Sports Med

View full text Add to dashboard Cite

Ulnar and posterior tibial motor nerve conduction velocity (NCV) was assessed in 91 athletes and nonathletes. The athletes included male weight lifters, swimmers, jumpers and male and female track sprinters and distance runners. NCV of the weight lifters was significantly faster than that of the other groups for both motor nerves. The male marathoners had the slowest posterior tibial NCV of all subject groups. A discriminant function analysis was successful in classifying 50.6% of the subjects into power-type, endurance-type, or untrained categories, based on ulnar and posterior tibial nerve conduction velocities. These results suggest that both genetic and environmental factors are important determinants of motor nerve conduction velocity.

show abstract

“…Changes in the neuromuscular junction and motor neuron can also occur with training, including cellular and subcellular adaptations in structure, modifications of transmission properties, and biochemical responses to stimulation (15,22). Associated with other forms of chronic physiologic overload are an altered histochemical stain intensity for various enzymes in the motor neuron suggesting an enhanced oxidative capacity and an enlargement of the motor neuron nucleolus (26), biochemical changes in the neuromuscular junction (21), and changes in the size of the neuron (23,27). The motor neuron, in turn, influences the protein composition and the maintenance of protein homeostass of the muscle (30).…”

Section: Discussionmentioning

confidence: 99%

Effects of Treadmill Running on Oxidative Capacity of Regenerated Skeletal Muscle*

Handel¹,

Watson²,

Troup³

et al. 1981

Int J Sports Med

View full text Add to dashboard Cite

The purpose of the present study was to examine the effects of treadmill running on the oxidative capacity of regenerated rodent skeletal muscle. The soleus, plantaris, and gastrocnemius muscles were removed under general anesthesia from one hindlimb of young female rats (N = 15). The visible "white" portion of the latter muscle was minced into 1 mm3 fragments and autotransplanted leaving both the tibial and sural nerves intact. Six animals were treadmill run daily beginning 4 days post-surgery. Intensity and duration were progressively increased such that by day 45 the animals were running 1 h at 21.5 m . min-1 up a 15% grade, The regenerated muscle homogenates had a significantly lower capacity for maximal pyruvate + malate oxidation and smaller mass relative to the contralateral gastrocnemius. The exercise program significantly increased these parameters, tending to normalize the values. Some factor associated with exercise stimulated recovery from the muscular trauma.

show abstract

Ventral motor neuron alterations in rat spinal cord after chronic exercise

Cited by 15 publications

References 6 publications

Rat α‐ and γ‐motoneuron soma size and succinate dehydrogenase activity are independent of neuromuscular activity level

Rat α‐ and γ‐motoneuron soma size and succinate dehydrogenase activity are independent of neuromuscular activity level

Ulnar and Posterior Tibial Nerve Conduction Velocity in Athletes

Effects of Treadmill Running on Oxidative Capacity of Regenerated Skeletal Muscle*

Contact Info

Product

Resources

About