Reinnervation and recovery of cat muscle receptors after long-term denervation

Barker, David J.; Scott, Jon; Stacey, Michael

doi:10.1016/0014-4886(86)90282-7

Cited by 33 publications

(19 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The afferent reinnervation of b, b2c spindle units (Banks, Barker & Stacey, 1982) was then examined in teased preparations and compared with their afferent innervation in three teased normal EDL muscles. We have made such comparisons in other work (Barker & Boddy, 1980;Barker et al 1985;Barker, Scott & Stacey, 1986;Banks & Barker, 1989) and have found no evidence to suggest that the silver-staining properties of regenerated afferent terminals are any different from those of normal ones.…”

Section: Methodsmentioning

confidence: 95%

“…By comparison, 49 % of the primary afferents responded normally after 6 weeks, 32 % after 8 and 87 % after 13. The ratio of I a: spindle II afferents, as identified by their responses to stretch (Barker et al 1986), was 1: 1-22 in the control animals and 1: 1-26 in the experimental series.…”

Section: Recovery Of Spindles After Devascularizationmentioning

confidence: 97%

“…2). Separation of the afferents into Ia and II according to the criteria of Barker et al (1986) gave mean velocities of 93-1 + 2-29 m s-and 42-1 + 2-29 m s-1, respectively. The mean velocities of the regenerated afferents were very similar, being 83-7 + 3-13 and 43-3 + 2-69 m s-1 for the I a and II afferents respectively, after 6 weeks recovery (n = 48), 93-8 + 2-56 and 45-6+2-15 m s-1 after 8 weeks (n = 61) and 82-7+ 155 and 37-3+2-69 ms-1 after 13 weeks (n = 103).…”

Section: Regenerated Spindlesmentioning

confidence: 99%

“…In each case the regenerating axons grow down intact endoneurial tubes to reinnervate intrafusal muscle fibres that, despite the different processes involved, re-establish a more or less normal profile of equatorial nucleation. In each case the regenerated primary endings have a reduced mean number of terminal bands, the reduction of 70 % from normal in those regenerated after devascularization corresponding to that seen in primary endings regenerated after nerve crush and restored to peroneus brevis spindles after a denervation period of 29 days (Barker et al 1986). (iii) After prolonged denervation of spindles brought about by repeated nerve crush, most of the reinnervating afferents give a normal pattern of response to ramp-and-hold stretch despite having grossly abnormal endings (Barker et al 1986).…”

Section: Recovery Of Spindles After Devascularizationmentioning

confidence: 99%

“…A. SCOTT stretch-responsive spindle afferents from the experiments, were classified as primary or secondary according to the criteria of Barker et al (1986). In each case the classifications showed a strong correlation with the bimodal distribution of the conduction velocities, though the overlap between primary and secondary afferents was greater in the regenerated population (Fig.…”

Section: Recovery Of Spindles After Devascularizationmentioning

confidence: 99%

See 4 more Smart Citations

Regeneration and recovery of cat muscle spindles after devascularization.

Barker¹,

Scott²

1990

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. We have assessed the sensory reinnervation and recovery of regenerated muscle spindles in extensor digitorum longus (EDL) 6, 8 and 13 weeks after the muscle, with its nerve left intact, had been devascularized. Recordings were made from the dorsal roots of the responses of single afferent fibres to ramp-and-hold stretch of the regenerated spindles whose sensory reinnervation was subsequently examined in teased, silver preparations.2. The spindle population in four normal EDL muscles ranged from 53 to 83 (mean 69); analysis of the afferent innervation of 166 normal b, b2 c spindles showed that 23 % had primary endings supplied by two Ia afferents. Regenerated spindles were identified as belonging to one of four groups in which afferents establish sensory endings on intrafusal muscle fibres in groups 1-3, but not in group 4. Sensory reinnervation was complete after 6 weeks recovery and similar proportions of group 1-3 spindles occurred after each recovery period, i.e. 58 % after 6 weeks, 65 % after 8 weeks and 62% after 13 weeks. We estimate that about half the original spindle population was lost owing to persistent ischaemic necrosis; that 30 % regenerated and acquired functional afferent connections (group 1-3 spindles); and that the total loss of spindle afferents was over 60 %. 3. The conduction velocities of the regenerated spindle afferents were very similar to those of normal EDL spindle afferents. The proportions that responded normally to ramp-and-hold stretch at the end of each recovery period increased from 58 % after 6 weeks to 61 % after 8 and 88% after 13. Other responsive spindle afferents were either predominantly phasic or only responded to supramaximal stretch. The proportions of these decreased as recovery progressed reducing from 19 % after 6 weeks to 9% after 13 weeks in the case of those giving predominantly phasic responses and from 23 % after 6 weeks to 3 % after 13 weeks in the case of those unresponsive to physiological stretch.4. The mean peak and held firing rates of regenerated spindle afferents responsive to 10 mm s-1 ramp-and-hold stretches were all significantly lower than normal. There was no marked trend towards higher firing rates after longer periods of recovery though, considered separately, the mean peak firing rates of the normally * Present address:

show abstract

Section: Methodsmentioning

confidence: 95%

Section: Recovery Of Spindles After Devascularizationmentioning

confidence: 97%

Section: Regenerated Spindlesmentioning

confidence: 99%

Section: Recovery Of Spindles After Devascularizationmentioning

confidence: 99%

Section: Recovery Of Spindles After Devascularizationmentioning

confidence: 99%

See 3 more Smart Citations

Regeneration and recovery of cat muscle spindles after devascularization.

Barker¹,

Scott²

1990

The Journal of Physiology

View full text Add to dashboard Cite

show abstract

Long‐term reiention of regenerative capability after denervation of skeletal muscle, and dependency of late differentiation on innervation

Gulati

1988

Anat. Rec.

View full text Add to dashboard Cite

The present study examines the influence of denervation on the regenerative ability of skeletal muscle in rats. Muscle denervation was achieved by transecting and ligating the cut ends of the sciatic nerve. Four to 48 weeks after denervation, the extensor digitorum longus (EDL) muscle was autotransplanted to induce muscle regeneration. The transplanted EDL muscles were examined at 1-12 weeks. Normal (i.e., no prior denervation) EDL muscle autotransplants were also examined for comparison. Denervation resulted in progressive atrophy of muscle, marked by a reduction in the size of myofibers and an increase in endomysialperimysial connective tissue. In spite of these alterations, typical events of muscle regeneration were invariably observed after transplantation. Initial myofiber degeneration and subsequent regeneration of myotubes occurred in a manner similar to normal muscle transplants. However, only a partial maturation of myotubes was observed in denervated muscles. These results show that extended denervation does not abolish the capability for muscle regeneration. The precursor myosatellite cells, proposed to be responsible for muscle regeneration, retain their regenerative potential after denervation. It is concluded, however, that the presence of intact innervation is crucial for the terminal differentiation and maturation of regenerating muscle.

show abstract

Location and completeness of reinnervation by two types of neurons at a single target: The feline muscle spindle

DeSantis¹,

Norman

1993

J of Comparative Neurology

View full text Add to dashboard Cite

Muscle spindles from the tenuissimus muscle of the cat were examined microscopically to assess the precision and completeness of reinnervation of intrafusal muscle fibers by efferent and afferent neurons. Positions of motor and sensory nerve terminals were charted relative to the cross-sectional area enclosed by the outer capsule of the spindle. Profiles of nerve endings were measured for normally innervated and reinnervated spindles. The tenuissimus was deprived of innervation by freezing its nerve, sometimes in conjunction with either spinal ganglion removal or ventral rhizotomy. Sensory and motor terminals occupied separate locales along the length of normal muscle spindles. Nerve terminals of efferent and afferent neurons were located in appropriate positions along the length of spindles when axons of both types of neurons regrew together and when either category of axon regenerated alone. Precise reinnervation of muscle spindles occurred in spite of a diminished diameter of intrafusal fibers. Repopulation of the spindle with motor endings was less complete than that by sensory endings, based on the proportion and size of the regenerated terminals. We conclude that under optimal conditions for axonal regrowth, efferent and afferent neurons reinnervate their respective regions along intrafusal muscle fibers but motor lags sensory reinnervation within the spindle. The mechanism by which positional specificity happens during reinnervation of intrafusal fibers requires neither an interaction between terminals of the two types of neurons nor target cells of normal bulk.

show abstract

Reinnervation and recovery of cat muscle receptors after long-term denervation

Cited by 33 publications

References 12 publications

Regeneration and recovery of cat muscle spindles after devascularization.

Regeneration and recovery of cat muscle spindles after devascularization.

Long‐term reiention of regenerative capability after denervation of skeletal muscle, and dependency of late differentiation on innervation

Location and completeness of reinnervation by two types of neurons at a single target: The feline muscle spindle

Contact Info

Product

Resources

About