Collateral Nerve Regeneration

Edds, Mac V.

doi:10.1086/399699

Cited by 315 publications

(99 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…There is no inconsistency between the occurrence of axonal sprouting after partial denervation of adult muscles (Edds, 1953;Guth, 1962) and our failure to detect sprouting of immature motor units. The lack of sprouting in immature muscles is presumably related to the large initial size of motor units.…”

Section: Discussionmentioning

confidence: 70%

Polyneuronal innervation of skeletal muscle in new‐born rats and its elimination during maturation.

Brown¹,

Jansen²,

Essen³

1976

The Journal of Physiology

751

462

View full text Add to dashboard Cite

SUMMARY1. The events taking place during the elimination of polyneuronal innervation in the soleus muscle of new-born rats have been studied using a combination of electrophysiological and anatomical techniques.2. Each immature muscle fibre is supplied by two or more motor axons which converge on to a single end-plate. There was no sign of electrical coupling between muscle fibres receiving multiple synaptic inputs. By the end of the second week after birth virtually all muscle fibres are innervated by only a single motor axon.3. The average tension produced by individual motor units, measured in terms of the percentage of the total muscle twitch tension, declined dramatically during the first 2 weeks after birth. During this period there was no significant change in the number of motor neurones innervating the soleus muscle. Thus, the disappearance of polyneuronal innervation reflects a decrease in the number of peripheral synapses made by each motor neurone.4. The decline in motor unit size was delayed, but not ultimately prevented, by the early surgical removal of all but a few motor axons to the soleus muscle. This procedure also caused a delay in the removal of polyneuronal innervation involving the remaining motor units.5. Following a crush of the soleus nerve in neonatal animals, regenerating axons usually returned to the original end-plates. Polyneuronal innervation was extensive at early stages of re-innervation and it disappeared during the second week after birth just as in normal muscles. 388 M. C. BROWN, J. K. S. JANSEN AND D. VAN ESSEN end-plates and in most fibres prevented re-innervation by the original nerve. In the small proportion of fibres that did become innervated through both the foreign and original nerves the end-plates were more than 1 mm apart, and both foreign and original nerve end-plates could persist indefinitely.7. Many cross-innervated fibres received multiple inputs through the foreign nerve. Some foreign end-plates were separated by distances ranging up to 1 mm. Polyneuronal innervation through the foreign nerve was completely eliminated during maturation but over a slightly longer period than in normal muscles. Apparently the elimination process can act over a distance up to but not much more than 1 mm.8. These observations suggest that there are several factors influencing the elimination of redundant inputs in immature muscles. Individual motor neurones appear to have an inherent tendency to withdraw the majority of their original complement of peripheral terminals. The determination of which particular synapses are to survive, however, seems to be made in the periphery by a selection among all the synapses that innervate a limited region of each muscle fibre. There may be a competitive interaction among synapses in which those belonging to smaller motor units are less likely to be eliminated, thereby leading to a relatively uniform size of the motor units in the soleus.

show abstract

Section: Discussionmentioning

confidence: 70%

Polyneuronal innervation of skeletal muscle in new‐born rats and its elimination during maturation.

Brown¹,

Jansen²,

Essen³

1976

The Journal of Physiology

751

462

View full text Add to dashboard Cite

show abstract

“…Since the cross-union operation resulted in the chromatolytic death of about two thirds of the spinal ganglion cells, their degenerating central terminals may have stimulated sprouting of adjacent Ia afferent fibres which then established the aberrant synaptic connexions on the Per motoneurones. This effect of degenerating nerve fibres was first demonstrated in partial muscle denervation (Hoffman, 1950(Hoffman, , 1951Edds, 1950Edds, , 1953, and it has also been found in the partially denervated sympathetic ganglion (Murray & Thompson, 1957) and in the spinal cord when spinal cord section caused degeneration of the descending tracts (McCouch, Austin, Liu & Liu, 1958).…”

Section: Discussionmentioning

confidence: 80%

Monosynaptic excitatory action on motoneurones regenerated to antagonistic muscles

Eccles¹,

Eccles²,

Magni³

1960

The Journal of Physiology

View full text Add to dashboard Cite

“…Evidence accumulated from experimental work has shown that, following a partial lesion in the nervous system, terminals with injured fibers degenerate and intact afferent fibers progressively sprout collaterally to occupy the evacuated regions. [18][19][20][21][22] Reorganization of the nervous system comprises degenerative and regenerative changes in the afferent neurons distal to the lesion sites, disorganization and reorganization of the whole network, and ultimately the new growth. [22][23][24][25][26][27][28][29] It is suggested that the process of degeneration, reorganization and sprouting results in an alteration of the 'synaptic zone', which is the very element of the nervous system transmitting information from one neuron to another, forming the basis of the reflex behavior.…”

Section: Mechanisms Underlying Rf Of Antagonist Muscles In Scimentioning

confidence: 99%

Reflex reciprocal facilitation of antagonist muscles in spinal cord injury

Xia

Rymer

2004

Spinal Cord

View full text Add to dashboard Cite

Study Design: Electromyographic study in complete and incomplete spinal cord injury (SCI). Objective: To examine the changes in the pattern of reciprocal inhibition between agonist and antagonist muscles in SCI. Settings: Sensory Motor Performance Program, Rehabilitation Institute of Chicago, IL, USA. Methods: Tendon taps were delivered manually with an instrumented hammer to the tendons of the tibialis anterior and soleus muscle in positions of full-ankle dorsiflexion and plantarflexion in eight subjects with complete SCI and eight subjects with incomplete SCI. Electromyographic activity (EMG) was recorded from ankle dorsiflexor and plantarflexor muscles. Tapping force was also recorded by a force sensor mounted to the tendon hammer, indicating the stimulus onset. Measures of reflex EMG magnitude and reflex latency were obtained for both agonist and antagonist muscles. The ratio of antagonist to agonist EMG was computed based on normalized EMG. Results: Substantial reflex responses occurred in both the stretched muscle and in its antagonist. The reflex in antagonist, which we term 'reciprocal facilitation (RF)', was most evident in subjects with incomplete SCI. The magnitude of RF was consistently greater than reflex responses in agonist muscles under all test conditions. The latency of the RF was comparable to that of monosynaptic reflex response. Conclusions: Following SCI, reciprocal organization of segmental reflexes at the ankle is often partially or completely suppressed, allowing reflex activation in antagonist muscles to be manifested. Possible mechanisms underlying these changes in neural organization are discussed.

show abstract

Collateral Nerve Regeneration

Cited by 315 publications

References 48 publications

Polyneuronal innervation of skeletal muscle in new‐born rats and its elimination during maturation.

Polyneuronal innervation of skeletal muscle in new‐born rats and its elimination during maturation.

Monosynaptic excitatory action on motoneurones regenerated to antagonistic muscles

Reflex reciprocal facilitation of antagonist muscles in spinal cord injury

Contact Info

Product

Resources

About