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Morphometric study of the neuromuscular synapses in the adult rat with special reference to the remodelling concept
Author(s) -
Tomas i Ferre J.,
Mayayo E.,
Fenoll i Brunet R.
Publication year - 1987
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1111/j.1768-322x.1987.tb00553.x
Subject(s) - biology , neuromuscular junction , anatomy , free nerve ending , muscle fibre , terminal (telecommunication) , process (computing) , motor endplate , neuroscience , synapse , fiber type , inhibitory postsynaptic potential , skeletal muscle , telecommunications , computer science , operating system
There is increasing morphologic evidence that neuromuscular synapses are not rigid structures in the mature muscles of adult animals. On the contrary, they may be submitted to a continuous process of remodelling. In silver‐impregnated sternocleidomastoid muscles of the young adult rat, we measured synaptic parameters such as nerve terminal length, the number of branching points of terminal arborization, and muscle fiber diameter, and used a morphometric approach to explore specific questions concerning neuromuscular remodelling. Quantitative data indicate that: (a) The complexity and maturation of the nerve endings in this muscle are very variable and the increase in branching points is not paralleled by an increase in terminal length; (b) Muscle fiber diameter is related only marginally to presynaptic parameters; (c) Accessory ending formation occurs when the original ending does not reach the mean size of endings in singly innervated areas; (d) The complexity of individual endings at dually innervated junctions is smaller than the mean development of singly innervated synapses, indicating the existence of some mutual inhibitory influence between closely spaced endings. Morphometric results suggest a continuous process of synaptic formation in this adult muscle.