Devo Lect 13 - Neural crest cells

Question 2

Neural crest cells

Answer 2

Produced from formation of neural tube; unique to vertebrates; called the fourth cell layer because they have so many functions; studied by Nicole LeDouarin (chimeras)

Question 3

Neural crest cells form

Answer 3

Neurons and glial cells for sensory, sympathetic and parasympathetic nervous system in the PNS; adrenal medulla (adrenalin); melanocytes (pigment); skeletal and connective tissue in head and heart

Question 4

Regions of neural crest

Answer 4

Forms most of bone in head, incl. inner ear; heart septum, blood vessels; dorsal root ganglia from trunk (sympathetic NS, and melanocytes)

Question 5

Migration of neural crest cells

Answer 5

Need to move to get to location; many obstructions, so they have certain pathways. One leader cell can form a physical path that is easier to follow, or leave a trail of molecules to follow (haptotaxis)

Question 6

Zebra stripes

Answer 6

Different patterns. Due to migration of neural crest cells. Exact pattern depends on timing of initial pattern (ie before body is done growing)

Question 7

Alan Turing

Answer 7

Famous mathematician. Formula for zebra striping patterns. Needs activator to make pigment, and inhibitor to block it.

Question 8

Jaguar pattern

Answer 8

Even more complex, not even full circles. Another math model. Again, it’s an interaction between activators and inhibitors.

Question 9

Pluripotency of Neural crest cells

Answer 9

Fate depends on migration and signals they are exposed to in that environment; eg. NGF, glucocorticords

Question 10

NGF

Answer 10

Nerve growth factor: blocks response to glucocorticoids and initiates sympathetic nerve development; discovered initially in nerve growth in tumors; main role in peripheral nervous system, so not as many uses for treatment as we thought

Question 11

Glucocorticoids

Answer 11

Affect neural crest cells in lower part of body like adrenal medulla; cells become endocrine cells with granules (with NT, hormone, etc)

Question 12

in vitro experiments on neural crest cells

Answer 12

put undifferentiated cells in dish and expose to different paracrine molecules, see what they become

Question 13

Carotid body

Answer 13

Chemoreceptors that measure O2 levels, helps regulate breathing; from neural crest cells

Question 14

Tony’s study on carotid bodies

Answer 14

Removed them from rats and exposed them to NGF (no change - no receptor) and hypoxia (increased growth); some plasticity to react to environment (ie O2 levels at altitude)