Building neural circuits Flashcards
(24 cards)
Identify the steps of brain development that occur pre-nataly in humans [2]
- genesis
- migration
Describe the formation of neural tube [2]
- neural plate folds in on itself to create neural tube
- morphogens organise the neural system
Where is the main site of proliferation go glutaminergic pyramidal cells
dorsal telencephalon
What is the main site of proliferation if GABAergic inhibitory
ventral telencephalon
describe the cortical plate in neuronal development [2]
where neurones settle
gives rise to neocortex
Identify they types of radial glial cells [2]
- neural progenitors
- multipotent stem cells
where of pyramidal neurones divide [1]
ventricular zone
- label the diagram
see diagram
Describe the symmetrical pyramidal cell division
- forms 2 radial glial cells
- expand the population of neural progenitors
describe asymmetrical cell division [4]
- results in one neural precursor
- which will differentiate and not divide again
- and radial glial cell
- which can undergo more cell division
Describe radial cell migration [5]
- immature cells
- migrate form ventricular zone to marginal zone
- to reach destination in cortical plate
- creates layers of cortex
- has bipolar shape
When does pyramidal neuronal differentiation occur
during migration
what is Sema3A [4]
- protein secreted by cell in marginal zone
- key for polarity in cortical plate
- repulses axon towards white matter
- attracts apical dendrite to the surface
Describe the experiment that showed the role of Sema3A [3]
- look at neurones in WT vs Sema3 -/- mice
- dendrites are thicker in WT
- axons thinner in WT
Describe how the limitation of cortex is formed [3]
- start layer 1
- then cell from the bottom layer ‘climb’ to next layer
- symmetric division occurs first
Explain what difference you would expect to see in WT cortex vs reelin - cortex [3]
- WT cells would be inverted, as leads to lamination
- reelin - would not see inversion
- reelin is essential in inside out migration
Briefly describe the gliogenesis of astrocytes and oligonucleotides [2]
- same progenitors as pyramidal cells
- but only after all pyramidal cells have been made
Where are PV+ and SOM+ interneurones formed
- medial ganglionic eminences (MGE) in the forebrain
What are the two main differences between MGE and caudal ganglionic caudal ganglionic eminence (CGE) [2]
- CGE more posterior than MGE
- MGE is the origin of PV/SOM+ and CGE is the origin of VIP+ cells
What is the most common form of migration of interneurones
tangenital migration
Describe tangenital migration [2]
- long distance
- regulated by external cues
Identify the main external cues involved in tangential migration [2]
- Sema 3A and Sema3F repel the interneurones (produced by striatum)
- while neregulin-1 attracts neurones
Describe the route taken by most SOM cells to get to the cortex [4]
- through the marginal zone
- axon remain in marginal zone
- axon can acton dendrites of pyramidal cells
- while soma continues to migrate
Describe the route to the cortex by PV/SST cells [2]
- 50/50 random as to which route they take
- there route they take determines where they will end up in the cortex
