Summary
The morphology of nerve terminals in the rat extensor digitorum longus and soleus muscles was studied with light microscopy in 13-week-old male animals after 6 weeks of treadmill running and compared with data from untrained controls. The terminals were stained with methylene blue. Physical training tended to increase the area and length of the nerve terminals in relation to the corresponding muscle fiber diameter, and to reduce the density of nerve terminal varicosities, but significant differences between the trained group and the control group were obtained only in the extensor digitorum longus muscle. The different degrees of effect on the nerve terminals in the two muscles may be due to different abilities to respond to the training, but may also be due to differences in work load caused by the training. The effect of training on extensor digitorum longus junctions may reflect some transformation from fast to slow morphological characteristics.
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References
Andonian MH, Fahim MA (1987) Effects of endurance exercise on the morphology of mouse neuromuscular junctions during ageing. J Neurocytol 16:589–599
Andonian MH, Fahim MA (1988) Endurance exercise alters the morphology of fast- and slow-twitch rat neuromuscular junctions. Int J Sports Med 9:218–223
Appell H-J (1984) Proliferation of motor end-plates induced by increased muscular activity. Int J Sports Med 5:125–129
Coërs C, Woolf AL (1959) The innervation of muscle. A biopsy study. Blackwell, Oxford
Eerbeek O, Kernell D, Verhey BA (1984) Effects of fast and slow patterns of tonic long-term stimulation on contractile properties of fast muscle in the cat. J Physiol 352:73–90
Eken T, Gundersen K (1988) Electrical stimulation resembling normal motor-unit activity: effects on denervated fast and slow rat muscles. J Physiol 402:651–699
Green HJ, Reichmann H, Pette D (1983) Fibre type specific transformations in the enzyme activity pattern of rat vastus lateralis muscle by prolonged endurance training. Pflügers Arch 399:216–222
Green HJ, Klug GA, Reichmann H, Seedorf U, Wiehrer W, Pette D (1984) Exercise-induced fibre type transitions with regard to myosin, parvalbumin, and sarcoplasmatic reticulum in muscles of the rat. Pflügers Arch 400:432–438
Hennig R, Lømo T (1985) Firing patterns of motor units in normal rats. Nature 314:164–166
Kardel KR, Dahl HA, Wærhaug O (1986) Training-induced modifications of the normal postnatal development of rat hindlimb muscles (Presented at The XXIII FIMS World Congress of Sports Medicine, Brisbane, Australia, September 20–28 1986)
Korneliussen H, Wærhaug O (1973) Three morphological types of motor nerve terminals in the rat diaphragm, and their possible innervation of different muscle fiber types. Z Anat Entwicklungsgesch 140:73–84
Labovitz SS, Robbins N, Fahim MA (1984) Endplate topography of denervated and disused rat neuromuscular junctions: comparison by scanning and light microscopy. Neuroscience 11:963–971
Lnenicka GA, Atwood HL (1985) Age-dependent long-term adaptation of crayfish phasic motor axon synapses to altered activity. J Neurosci 5:459–467
Lnenicka GA, Atwood HL, Marin L (1986) Morphological transformation of synaptic terminals of a phasic motoneuron by long-term tonic stimulation. J Neurosci 6:2252–2258
Lømo T, Wærhaug O (1985) Motor endplates in fast and slow muscles of the rat: What determines their difference? J Physiol (Paris) 80:290–297
Mytskan BM (1977) Quantitative changes in myoneural synapses and capillaries following physical exertion. Bull Exp Biol Med NY 83:101–103
Nyström B (1968) Postnatal development of motor nerve terminals in “slow-red” and “fast-white” cat muscles. Acta Neurol Scand 44:363–383
Stebbins CL, Schultz E, Smith EL (1985) Effects of chronic exercise during aging on muscle and end-plate morphology in rats. J Appl Physiol 58:45–51
Tomas J, Fenoll R, Santafé M, Batlle J, Mayayo E (1989) Motor nerve terminal morphologic plasticity induced by small changes in the locomotor activity of the adult rat. Neurosci lett 106:137–140
Westgaard RH, Lømo T (1988) Control of contractile properties within adaptive ranges by patterns of impulse activity in the rat. J Neurosci 8:4415–4426
Wærhaug O (1992) Postnatal development of rat motor nerve terminals. Anat Embryol 185:115–123
Wærhaug O, Korneliussen H (1974) Morphological types of motor nerve terminals in rat hindlimb muscles, possibly innervating different muscle fiber types. Z Anat Entwicklungsgesch 144:237–247
Wærhaug O, Korneliussen H, Sommerschild H (1977) Morphology of motor nerve terminals on rat soleus muscle fibers reinnervated by the original and by a “foreign” nerve. Anat Embryol 151:1–15
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Wærhaug, O., Dahl, H.A. & Kardel, K. Different effects of physical training on the morphology of motor nerve terminals in the rat extensor digitorum longus and soleus muscles. Anat Embryol 186, 125–128 (1992). https://doi.org/10.1007/BF00174949
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DOI: https://doi.org/10.1007/BF00174949