Week 1 Tutorial Flashcards
What important event occurs in the walls of the neural tube?
Corticogenesis and formation of cortical layers causing the neural tube to become narrower
What will the hollow part of the neural tube become in the adult?
Ventricles and central canal
Which layer of the neocortex is the most superficial?
Layer I
Which layer of the neocortex is the deepest?
Layer VI
What are the general properties of Layer I of the neocortex?
Molecular layer, top down info, a few horizontal cells of CR, afferent thalamocortical tract
What are the two main classes of cortical neurons?
- Excitatory
- Inhibitory
What happens to the staining pattern when the virus is injected earlier?
Staining occurs more deeply
What is the hypothesis regarding the staining pattern based on the day of injection?
Excitatory neurons are moving more superficially
What does the ‘inside-out’ pattern of corticogenesis indicate?
Excitatory neurons migrate up radial glial cells
Where would GABAergic neurons have been generated?
Subcortically
What migration pattern do GABAergic neurons undertake?
Tangential migration
What migration pattern do glutamatergic neurons undertake?
Radial migration up radial glial cells
What kinds of cues help growth cones navigate?
- Attractive cues
- Repulsive cues
What effect does netrin have on RGC growth cones?
Attracts the growth cones
What happens to the growth cone when both netrin and laminin are present?
The growth cone grows away from netrin
What is the percentage of RGCs that stay ipsilateral in mice?
About 3% from a specific part of the retina stay ipsilateral.
What axonal guidance molecule is highly expressed at the midline of the optic chiasm in embryonic mice?
EphrinB2.
What receptor is specific to the ventrotemporal part of the retina and binds to ephrinB2?
EphB1.
What hypothesis can be formed about EphB1 and ephrinB2 in establishing binocular visual circuits?
EphB1 and ephrinB2 interactions may prevent ventrotemporal growth cones from crossing the midline, causing them to grow ipsilaterally.
What happens to the ipsilateral projection after deletion of EphB1 in mice?
The ipsilateral projection is non-existent.
What type of axonal guidance mechanism is involved in determining the laterality of RGC projections?
Chemoattractive axonal guidance mechanisms.
When is ephrinB2 expressed at the optic chiasm in humans?
Around 11 weeks of gestation.
How does the expression of EphB1 in humans differ from that in mice?
EphB1 is more widespread in the human RGC layer, covering the whole temporal half of the retina.
