Neurodevelopment 2 Flashcards
Axon sizes can vary from
less than 1mm to more than 1 m
Phase 1 of neural development
Cells develop independently and locally in embryo
Phase 2 of neural development
Axons and dendrites grow out along specific routes setting up a provisional but orderly network of connections between diff parts of nervous system
** synapse also form** “provisionally” or loosely
Phase 3 of neural development
Continues into adult life
Connections are adjusted and refined through interactions with distal regions via electrical signals
Strengthening synapses and building new ones too
CNS
Brain, spinal cord and retina derived from neural tube
PNS
Nerves, sensory neurons derived from neural crest
Floor plate of morphogen secrete
Sonic hedgehog protein
Roof plate of morphogen secrete
BMP and Wnt proteins
Growth cone of neuron
tip axon/dendrite with irregular, spiky enlargement
Chemotactic factors
Secreted by the cells, acting as a guidance factors at strategic points along the path
Nectrin, Slit and semaphorin are examples of
Chemotactic factors
Delta notch signaling controls differentiation into neurons by way of
lateral inhibition and positive feedback
BMP protein functions is to
pattern formation, differentiation, secretion of extracellular matrix
Sonic hedgehog protein function is to
activate latent genes
Neural crest cells in addition to PNS neurons they also produce (2)
epinephrine producing cells of the adrenal gland
Skeletal and connective tissue components of the head
