title: Different neurotrophins are expressed and act in a developmental sequence to promote the survival of embryonic sensory neurons.
abstract: To investigate if different neurotrophins regulate the survival of neurons at successive developmental stages, we studied the effect of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) on the survival of mouse trigeminal neurons at closely staged intervals in development. We show that during the earliest stages of target field innervation trigeminal neurons display a transitory survival response to BDNF and NT-3. This response is lost as the neurons become NGF-dependent shortly before neuronal death begins in the trigeminal ganglion. BDNF and NT-3 mRNAs are expressed in the peripheral trigeminal target field before the arrival of the earliest axons and the onset of NGF mRNA expression. The levels of BDNF and NT-3 mRNAs peak during the early stages of target field innervation and decline shortly after the loss of neuronal responsiveness to BDNF and NT-3. Our study provides the first clear evidence that different target-derived neurotrophins can act sequentially to promote the survival of developing neurons.
authors.affiliation: Department of Anatomy, St. George's Hospital Medical School, Tooting, London, UK.
authors.forename: V L
authors.initials: VL
authors.lastname: Buchman
authors.forename: A M
authors.initials: AM
authors.lastname: Davies
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor; D002470:Cell Survival; D002610:Cheek / Q000294:innervation; D005786:Gene Expression Regulation; D005865:Gestational Age; D051379:Mice; D009024:Morphogenesis / Q000235:genetics; D009414:Nerve Growth Factors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D016501:Neurites / Q000648:ultrastructure; D009475:Neurons, Afferent / Q000166:cytology*; D020933:Neurotrophin 3; D009924:Organ Culture Techniques; D012249:Rhombencephalon / Q000196:embryology / Q000378:metabolism; D012867:Skin / Q000294:innervation / Q000378:metabolism; D013997:Time Factors; D012668:Trigeminal Ganglion / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D014276:Trigeminal Nerve / Q000166:cytology / Q000196:embryology*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D020933:Neurotrophin 3