In:
Muscle & Nerve, Wiley, Vol. 60, No. 6 ( 2019-12), p. 790-800
Abstract:
Reduced expression of the vesicular acetylcholine transporter (VAChT) leads to changes in the distribution and shape of synaptic vesicles (SVs) at neuromuscular junctions (NMJs), suggesting vesicular acetylcholine (ACh) as a key component of synaptic structure and function. It is poorly understood how long‐term changes in cholinergic transmission contribute to age‐ and disease‐related degeneration in the motor system. Methods In this study we performed confocal imaging, electrophysiology, electron microscopy, and analyses of respiratory mechanics of the diaphragm NMJ components in 12‐month‐old wild‐type (WT) and VAChTKD HOM mice. Results Diaphragms of NMJs of the VAChTKD HOM mice were similar to those in WT mice in number, colocalization, and fragmentation of pre−/postsynaptic components. However, they had increased spontaneous SV exocytosis, miniature endplate potential frequency, and diminished MEPP amplitude. No impairment in respiratory mechanics at rest was observed, probably due to the large neurotransmission safety factor of the diaphragm. Discussion The present findings help us to understand the consequences of reduced ACh release at the NMJs during aging.
Type of Medium:
Online Resource
ISSN:
0148-639X
,
1097-4598
Language:
English
Publisher:
Wiley
Publication Date:
2019
detail.hit.zdb_id:
1476641-3
SSG:
12
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