Learn More
During development, neuronal survival is regulated by the limited availability of neurotrophins, which are proteins of the nerve growth factor (NGF) family. Activation of specific trk tyrosine kinase receptors by the neurotrophins blocks programmed cell death. The trkA-specific ligand NGF has also been shown to activate the non-tyrosine kinase receptor p75,(More)
The developing chick retina undergoes at least two discrete periods of programmed cell death. The earlier period coincides with the main onset of neuron birth and migration (embryonic day 5-7), whereas the latter one corresponds to the well-documented process of retinal ganglion cell death following tectal innervation (embryonic day 10-14; Rager, G. H.(More)
The survival effects of brain-derived neurotrophic factor (BDNF) on the ganglion cells of the chick retina were studied in vitro at different embryonic ages. We found these effects to be strongly age-dependent: at E5, when the first ganglion cell axons have crossed the optic chiasm, but not yet reached the tectum, ganglion cells survived on a laminin(More)
The neurotrophic proteins BDNF and NGF are related in their primary structures, and both have high- and low-affinity receptors on their responsive neurons. In this study, we investigate the extent to which these receptors can discriminate between BDNF and NGF. We found that a 1000-fold excess of the heterologous ligand is needed to reduce binding to the(More)
The effects of neurotrophins brain-derived neurotrophic factor and neurotrophin-3 on cultured dissociated cells from chick retina were studied at several embryonic ages from day 4 to day 13. Precursor cells from days 4-7 retinas proliferated in vitro and, after 20 h in culture, a proportion of them underwent spontaneous differentiation, as judged by both(More)
The development of the nervous system is dependent on a complex set of signals whose precise co-ordination ensures that the correct number of neurones are generated. This regulation is achieved through a variety of cues that influence both the generation and the maintenance of neurones during development. We show that in the chick embryo, stratified retinal(More)
When chick embryos are treated with a monoclonal antibody specifically blocking the activity of neurotrophin-3 (NT-3), the development of the retina is profoundly affected. Fewer axons are found in the optic nerve, and the retina shows abnormalities in all layers. Early during retinogenesis, the proportion of dividing cells is higher in NT-3-deprived(More)
The extracellular matrix protein vitronectin and its mRNA are present in the embryonic chick notochord, floor plate and in the ventral neural tube at the time position of motor neuron generation. When added to cultures of neural tube explants of developmental stage 9, vitronectin promotes the generation of motor neurons in the absence of either notochord or(More)
An important step in the development of peripheral sensory and sympathetic neurons is the onset of the survival response and dependence on the presence of nerve growth factor (NGF) or other neurotrophic factors. We have recently observed that immature sympathetic neurons from 7-day-old chick embryos are unable to become NGF-responsive in vitro and we have(More)
Cultured neurons from bdnf-/- mice display reduced densities of synaptic terminals, although in vivo these deficits are small or absent. Here we aimed at clarifying the local responses to postsynaptic brain-derived neurotrophic factor (BDNF). To this end, solitary enhanced green fluorescent protein (EGFP)-labeled hippocampal neurons from bdnf-/- mice were(More)