The origins and birth of neurons 2 Flashcards
What does BMP stand for?
Bone morphogenic protein
What type of receptor is the BMP receptor?
Serine-threonine kinase
How many subunits make up the BMP receptor?
2–> type 1 and type 2
What does binding of BMPs trigger in the receptor?
Their dimerisation
How do BMPs bind to their receptors?
As dimers
What do the BMP receptors do when bound to, and consequently dimerised?
phosphorylate SMAD-1
What does Smad-1 do once phosphorylated?
Binds to Smad-4 and causes a change in TF expression
Which gened does the Smad-1, Smad-4 complex affect?
Inhibits neural gene expression and activates epidermal gene expression
What is neurulation?
the neural plate bends up and later fuses to form the hollow tube that will eventually differentiate into the brain and the SC of the CNS
What folding of the neural plate driven by?
Shape changes at key areas
What is cephalisation?
Formation of the head
What is segmentation?
Subdividing the neural tube into different structures
What is the prosencephalon?
Forebrain
What does the prosencephalon differentiation into?
Telencephalon and diencephalon
What does the telencephalon go on to form?
Cerebral hemispheres, hippocampus
What does the diencephalon go on to form?
optic vesicle
How are the ends of the neural plate/tube signalled to so that they know what structure to differentiate into?
Molecular gradient signalling–> molecules that have a high conc at one end and low at the other
Wnt concentration in the neural tube?
High at the rear, low at the front
No wnt to form the forebrain
What is the ventral surface next to?
The mesoderm
What is the mesoderm in the neural tube called?
The notochord
What is the notochord?
Rod like structure at the bottom of the neural tube, opposite to the epidermis
How does the notochord and epidermis define an axis?
Norochord is the ventral region, the epidermis is the dorsal region
How does the neural tube give rise to diff types of neurons in diff places?
Where the place is (more dorsal, more ventral or somewhere in the middle)
Done by the cells reading the gradient of signals
Which signals are used in neural tube development in the dorsal ventral axis?
Sonic hedgehog (ventral to dorsal)
BMP4 and BMP7 (dorsal to ventral)
