Development of the Nervous system Flashcards
What is the function of the radial glia in development?
Act as a scaffold for the developing neurons
How are motor neurons of the spinal cord organised topographically?
Distal limbs are controlled by motor neurons on the distal aspect of the spinal cord
What signal induces the formation of the floor plate and where does it come from?
Sonic hedgehog and the notochord
What do new neurons travel up to reach the cortex?
The radial glia
What do growth cones consist of?
Cytoskeleton
At what level is there dysfunction when a eye is kept shut in the development of a kitten
The visual cortex
What is fragile X syndrome caused by?
A mutation in the fragile X mental retardation gene (FMR1)
Which part of the spinal cord has sensory information?
The dorsal horn
What induces the development of ventral horn motor neurons of the spinal cord?
Factors released from the floor plate
How do interneurons in the spinal cord come about?
Factors (motor neuron factor) released for the motor neurons
What is the critical period for vision and hearing in humans?
The first 10 years
How does the brain appear in lissencephaly?
Smooth, unfolded surface.
What is induction in the context of neural development?
The next stage in development of the specific structures, eg the somites developing muscle and bone
What is the significance of the pioneer axons?
They lay down initial axon tracts they proceeding neurons follow
What develops first, the head or tail or the neural tube?
Head
What is vesiculation of the neural tube?
The narrow tube develops bubbles
Where are neural stem cells located in the developing cortex?
In the ventricular zone (at the ventricular surface)
How do new cells develop in relation to the neuroepithelium?
The migrate through the neuroepithelium and move up towards the cortex, away from the lumen of the tube
Where do neural crest cells come from?
Top of the neural tube
The prosencephalon splits into what?
The diencephalon and the telencephalon
What are growth cones?
Caps on the end of axons that tow developing axons into position
What is the neural plate derived from?
A plate of skin
What is the name of the disease where there is not closure of the caudal end of the neural tube?
Spina bifida
What happens to the structure of the nervous system postnatally?
Refinement - particularly at the level of the synapses
What is the precursor structure of the forebrain?
The prosencephalon
Why don’t you get incomplete folding of the neural tube in multiple regions?
Because the regions close independently
Disorders of neuronal migration include?
Lissencephaly
What are some derivative of the neural crest cells?
Peripheral nervous system
Melanocytes
Dentine
Muscle, cartilage and bones of the skull, face, jaw and pharynx
What is anacephaly?
Incomplete closure of the neural tube around the vault of the skull - brain doesn’t develop fully - still born
In which part of the spinal cord are motor located?
Ventral horn
Is the retina part of the CNS or PNS?
CNS
How do axons develop?
They extend out from the cell body
What is the developmental precursor of the retina?
Optic vesicle
What directs the development of the growth cones?
Local growth factors
What happens to the neural plate for it to become a tube?
The neural groove forms and its lip rise up and connect creating a lumen inside
Where does the neural tube close last?
At the bottom of the spinal cord
What is the most common cause of male autism?
Fragile X syndrome
