Aswith nerve growth factors, they form a family of (diffusible) proteins secretedby target cells, generally having attractive influences on outgrowing axons. They not only attract, but also repel other neurons. Netrin-1 is formed and secreted in thefloor plate of the neural tube and netrin-2 in the lower regions of the neuraltube. Netrin-1 is credited with being …
Author Archives: Brian Hopkins
Nerve growth factor (NGF)
A neurotrophic substance emitted from smooth muscle and tissues innervated by neurons. Its role is thought to be the guidance of neuronal growth during embryonic development, especially in the peripheral nervous system, and in the maintenance of sympathetic and sensory neurons thereafter. In fact, it is crucial for thesurvival of sympathetic and sensory neurons, and …
Neonatal synesthesia
Synesthesia isa clinical condition in which a sensation in one sense modality triggers anarbitrarily related sensation in another (or the same) modality. Somedevelopmental theorists (notably Maurer, Gibson, & Spector, 2012, see Harvey, 2013, for some critical comments) have argued thatperception is synesthetic in early life on the basis that newborns likelypossess much more in the way …
Neonatal death
The death of a live born infant within the first 28 days of life (in some countries neonatal is defined as the first 7 days of life). See Birth prevalence, Child death, Fetal death, Infant death, Infanticide, Newborn
Neocortex
Same as cerebral cortex. ‘Neo’ refers to the now-discredited belief that the structure is entirely new in mammals. See Cerebral cortex (or pallium), Infantile amnesia, Isocortex
Neo-Piagetian theories of cognitive development
Theories of cognitive development that preserve important tenets of Piaget’s theory of cognitive development while addressing trenchant criticisms of the theory. Neo-Piagetian theorists are generally not committed to a strong doctrine of developmental stages (structures d’ensemble), but attempt to retain the notion of domain-specific transformations of cognitive structures in terms of a series of levels, …
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Neo-Darwinism
Sometimes it is equated with the Modern synthesis, which is not strictly speaking correct as it was a fusion between the ideas contained in the Origin of species (1859) and the mechanisms of heredity discovered by Gregor Mendel (1822-1894). However, by the turn of the 20th century, neo-Darwinism has become part of a three-way split …
Necessary and sufficient conditions
A necessary (or sine qua non) condition is one without which development would not be forthcoming. Such conditions have been sought in deprivation studies. A sufficient condition is one with which development does occur, and as such has been the concern of enrichment or special experience studies. Necessary and sufficient conditions do not have to …
Nature-nurture debate
An almost outmoded controversy over the relative importance of heredity or genes (nature) and environment or experience (nurture) as independent causal agents in the development of the individual. Thus it amounts to a short-hand summary of distinctions between genetically based and experientially derived functions. Contrasting the terms ‘nature’ and nurture’ was first done by Richard Mulcaster (1530-1611), …
Natural selection
A major force in evolution co-discovered by Charles Darwin (1809-1882) and Alfred Russel Wallace (1823-1913), natural selection serves as a filter in preserving reproductively successful developmental outcomes and acting against outcomes that impede successful reproduction and the rearing of offspring. See Baldwin effect, Co-evolution, Darwinism, Evolutionary biology, Evolutionary niche theory, Modern synthesis, Natural selection, Neo-Darwinism, …