Axotomy Induces Fusimotor-free Muscle-spindles In Neonatal Rats

Title

Axotomy Induces Fusimotor-free Muscle-spindles In Neonatal Rats

Creator

Kucera J; Walro J

Publisher

Neuroscience Letters

Date

1992
1992-03

Description

Crushing the nerve to the medial gastrocnemius (MG) muscle at birth and administering nerve growth factor to rats afterwards results in a reinnervated muscle with supernumerary muscle spindles, some of which must have formed de novo. Structure and innervation of spindles in the reinnervated MG muscles were studied in serial 1-mu-m transverse sections. Two types of spindle-like encapsulations were observed. The prevalent type consisted of one to three small diameter intrafusal fibers with features of nuclear chain fibers or infrequently a nuclear bag fiber. The second type of encapsulation consisted of the small-diameter fibers located in a compartment which abutted a compartment containing a large diameter extrafusal fiber. All intrafusal fibers in spindles of the experimental muscles were innervated by afferents, but most of them (85%) were devoid of efferent innervation. Thus, immature fusimotor neurons may be more susceptible than spindle afferents to cell death after axotomy at birth.

Subject

fibers; fusimotor system; intrafusal; intrafusal muscle fiber; nerve; Neurosciences & Neurology; spindle development

Format

Journal Article or Conference Abstract Publication

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Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

216-218

Issue

2

Volume

136

Citation

Kucera J; Walro J, “Axotomy Induces Fusimotor-free Muscle-spindles In Neonatal Rats,” NEOMED Bibliography Database, accessed March 4, 2021, https://neomed.omeka.net/items/show/10562.

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