The neuromuscular junction of Xenopus tadpoles: Revisiting a classical model of early synaptogenesis and regeneration. (December 2018)

• Record Type: Journal Article
• Authors: Bermedo-García, Francisca; Ojeda, Jorge; Méndez-Olivos, Emilio E.; Marcellini, Sylvain; Larraín, Juan; Henríquez, Juan Pablo
• Is Part Of: Mechanisms of development. Volume 154(2018)
• Page Start: 91
• Page End: 97
• Publication Date: 2018-12
• Subjects: Neuromuscular junction -- Xenopus -- Synaptogenesis -- Regeneration; Developmental biology -- Periodicals; Molecular biology -- Periodicals; Developmental Biology -- Periodicals; Molecular Biology -- Periodicals; Biologie du développement -- Périodiques; Biologie moléculaire -- Périodiques; Developmental biology; Molecular biology; Periodicals; Electronic journals; 571.8
• DOI: 10.1016/j.mod.2018.05.008
• Languages: English
• ISSNs: 0925-4773

Abstract

Abstract: The frog neuromuscular junction (NMJ) has been extensively used as a model system to dissect the mechanisms involved in synapse formation, maturation, maintenance, regeneration, and function. Early NMJ synaptogenesis relies on a combination of cell-autonomous and interdependent pre/postsynaptic communication processes. Due to their transparency, comparatively easy manipulation, and remarkable regenerative abilities, frog tadpoles constitute an excellent model to study NMJ formation and regeneration. Here, we aimed to contribute new aspects on the characterization of the ontogeny of NMJ formation in Xenopus embryos and to explore the morphological changes occurring at the NMJ after spinal cord injury. Following analyses of X . tropicalis tadpoles during development we found that the early pathfinding of rostral motor axons is likely helped by previously formed postsynaptic specializations, whereas NMJ formation in recently differentiated ventral muscles in caudal segments seems to rely on presynaptic inputs. After spinal cord injury of X . laevis tadpoles our results suggest that rostral motor axon projections help caudal NMJ re-innervation before spinal cord connectivity is repaired. Highlights: In Xenopus embryonic NMJs, rostral motor axons innervate preformed AChR clusters. Presynaptic axons drive NMJ formation in ventral muscles of new caudal segments. After SCI, rostral motor axon collaterals help caudal NMJ re-innervation.