Development of neuromuscular junctions on small mesenteric arteries of the rat.

摘要: This ultrastructural study has investigated the development of innervation second order mesenteric arteries from ileum region rat intestine, particularly, time course formation plexus varicose axons around arteries, and autonomic neuromuscular junctions. The points studied were postnatal days-2, -4, -8 -13. revealed that junctions with mature structural characteristics occurred at ~2 weeks postnatal. developed predominantly between day-4 day-13, which agrees previous light microscopy studies catecholamne containing nerves similar vessels. At day-2 day-4, lacked varicosities mainly contained in large bundles located outer adventitia. medio-adventitial border consisted a dense layer extracellular matrix fibroblasts. By day-8, there more most distributed smaller bundles. Some had grown through adventitia to lie axon also observed. formed rudimentary contacts. significantly contacting compared day-8. They structurally mature, being twice size three times number synaptic vesicles consistently mitochondrion. Conversely, contact areas both points. organisation associated prejunctional membrane, was evident day-8 but no presynaptic membrane specialisations putative neurotransmitter release sites found skeletal aggregation small pronounced day-13 some having specialisations. Comparison structure developing similarities.