The role of synapsin I, a synaptic vesicle-associated phosphoprotein, in the maturation of nerve-muscle synapses was investigated in nerve-muscle co-cultures prepared from Xenopus embryos loaded with the protein by the early blastomere injection method. The stage of maturation of the synapses was analysed by electron microscopy as well as by whole-cell patch-clamp recording. The acceleration in the functional maturation of neuromuscular synapses induced by synapsin I was accompanied by a profound rearrangement in the ultrastructure of the nerve terminal. Nerve terminals formed by synapsin I-loaded neurons were characterized by a higher number of small synaptic vesicles organized in clusters and predominantly localized close to the nerve terminal plasma membrane, a smaller number of large dense-core vesicles and no significant change in the number of coated vesicles. Precocious development of active zone-like structures as well as deposition of basal lamina into the synaptic cleft were also observed at these synapses. These results support a role for synapsin I in the architectural changes which occur during synaptogenesis and lead to the maturation of quantal neurotransmitter release mechanisms.

Accelerated structural maturation induced by synapsin I at developing neuromuscular synapses of Xenopus laevis / Valtorta, Flavia; Iezzi, N; Benfenati, F; Lu, B; Poo, M. M; Greengard, P.. - In: EUROPEAN JOURNAL OF NEUROSCIENCE. - ISSN 0953-816X. - 7:2(1995), p. 261-70.

Accelerated structural maturation induced by synapsin I at developing neuromuscular synapses of Xenopus laevis

VALTORTA, FLAVIA
Primo
;
1995-01-01

Abstract

The role of synapsin I, a synaptic vesicle-associated phosphoprotein, in the maturation of nerve-muscle synapses was investigated in nerve-muscle co-cultures prepared from Xenopus embryos loaded with the protein by the early blastomere injection method. The stage of maturation of the synapses was analysed by electron microscopy as well as by whole-cell patch-clamp recording. The acceleration in the functional maturation of neuromuscular synapses induced by synapsin I was accompanied by a profound rearrangement in the ultrastructure of the nerve terminal. Nerve terminals formed by synapsin I-loaded neurons were characterized by a higher number of small synaptic vesicles organized in clusters and predominantly localized close to the nerve terminal plasma membrane, a smaller number of large dense-core vesicles and no significant change in the number of coated vesicles. Precocious development of active zone-like structures as well as deposition of basal lamina into the synaptic cleft were also observed at these synapses. These results support a role for synapsin I in the architectural changes which occur during synaptogenesis and lead to the maturation of quantal neurotransmitter release mechanisms.
1995
Animals; Cells, Cultured; Nerve Endings; Neuromuscular Junction; Synapses; Synapsins; Xenopus laevis
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11768/61369
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