Morphological variability is greater at developing than mature mouse neuromuscular junctions

• DOI: 10.1111/joa.13228
• Publication Date: 2020-06-13T07:19:30Z
• Authors: Aleksandra M. Mech; Anna‐Leigh Brown; Giampietro Schiavo; James N. Sleigh
• Keywords: Motor Endplate; Synaptic cleft; Synaptophysin; Motor nerve

Abstract The neuromuscular junction (NMJ) is the highly specialised peripheral synapse formed between lower motor neuron terminals and muscle fibres. Post‐synaptic acetylcholine receptors (AChRs), which are found in high density membrane, bind to released into synaptic cleft of NMJ, thereby enabling conversion action potentials contractions. NMJs have been studied for many years as a general model formation, development function, known be early sites pathological changes diseases. However, information limited on diversity different muscles, how morphology during development, relevance these parameters neuropathology. Here, this crucial gap was addressed using robust standardised semi‐automated workflow called NMJ‐morph quantify features pre‐ post‐synaptic NMJ architecture an unbiased manner. Five wholemount muscles from wild‐type mice were dissected compared at immature (post‐natal day, P7) adult (P31−32) timepoints. inter‐muscular variability greater mature AChR than that pre‐synaptic terminal. Moreover, developing showed differences across synapse, perhaps due observed distinctions growth muscles. Nevertheless, amount nerve contact consistent, suggesting denervation can reliably mouse models neurodegeneration. Additionally, endplate diameters correlated with fibre type, independently diameter. Altogether, work provides detailed healthy five anatomically functionally distinct delivering useful reference data future comparison disease models.