title: [Influence of nerve growth factor (NGF) on formation of synapses in newt embryonic neural tube].
abstract: Under the influence of the nerve growth factor (NGF) a general stimulation of the synthetic processes, especially protein synthesis, occurs in the neuroblasts. The morphological counterpart is an hypertrophy of the nucleoli and spiralization of nucleolonema, an increase of the number of ribosomes with the persistence of a specific organization for each stage of development, then the proliferation of the granular endoplasmic reticulum and the modification of the predominant shape of mitochondria, which becomes annular, their outer surface being largely increased. The nutrient stores are quickly exhausted, with an accelerated disintegration of yolk droplets. There is an obvious increase in the number of non-synaptic contacts (puncta adherentia) between processes of neuroblasts and neighbouring nervous structures, and also an acceleration of formation of typical synaptic zones, indicating that NGF stimulates the functional maturation of the nervous system.
mesh_terms: D000818:Animals; D002490:Central Nervous System / Q000196:embryology* / Q000648:ultrastructure; D009414:Nerve Growth Factors / Q000494:pharmacology*; D012455:Salamandridae; D013569:Synapses / Q000648:ultrastructure
chemical_list: D009414:Nerve Growth Factors
vernacular_title: Influcence du facteur de croissance nerveuse (NGF) sur la genèse de synapses dans le tube neural d'embryons de tritons