06-10 - The overall process of nervous system development...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
The overall process of nervous system development 1.The specification of neural cell (neuron or glial cell) identity; 2. The migration of neurons and outgrowth of axons to their targets 3. The formation of synapses with target cells; 4. The refinement of synaptic connections through the elimination of axon branches and cell death.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Specification of cell identity in the nervous system Fig 10.2 Cross-section of a Drosophila early gastrula showing the location of the neurectoderm Neurectoderm: neurogenic zone Proneural clusters (proneural genes: achaete-scute ), ~30 neuroblast per hemisegment--- neurons; Ectoderm: glioblasts ( glial cells missing : gcm );
Background image of page 2
Fig 10.3 Organization of invertebrate and vertebrate neuroepithlium into three columns of neural precursors Each column expresses a specific homeobox gene
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Fig 10.4 The role of Notch signaling in lateral inhibition in neural development in Drosophila One cell (random event) in the cluster starts to express Achaete protein at a higher level than the other cells--- neuroblast, others becoming epidermal cells
Background image of page 4
Fig 10.5 The formation of neural cells from neuroblasts in Drosophila by asymmetric cell division Numb determines the cell to become the ganglion mother cell that will give rise to neurons. IIb: give rise to a sensory neuron and a sheath cell; IIa: give rise to a hair cell and a socket cell
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
The neuroblasts of the sensory organs of adult Drosophila are already specified in the imaginal disc (Sensory organ precursors) Fig 10.6 Sensory bristles in the epidermis of adult Drosophil
Background image of page 6
Fig 10.7 Specification of sensory bristles in the Drosophila wing
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
The vertebrate nervous system is derived from the neural plate Fig 10.8 Neural tube: the cells remain within the neural tube give rise to CNS (brain and spinal cord); Neural crest cells: give rise to both the sensory neurons of the peripheral nervous system and to autonomic ( T ) nervous system Anterior-posterior axis: hox genes; dorso-ventral axis: BMP/Shh
Background image of page 8
Fig 10.9 Lateral inhibition specifies single cells as neuronal precursors in the vertebrate nervous system In Xenopus , medial stripes: motor neurons; lateral stripes: interneurons and sensory neurons; Neurogenin: a basic helix-loop-helix TF; is distantly related to the Archaete and Scute proteins of Drosophila Inhibition of Delta: more neurogenin: more neurons
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Neurons are formed in the proliferative zone of the neural tube and migrate outwards In both brain and spinal cord, all neurons and glia arise from a proliferative layer of epithelial cells that lines the lumen of the neural tube. Ventricular zone: T
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 40

06-10 - The overall process of nervous system development...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online