Ngn1 Ngn2 two waves of neuronal diff in piriform, JNeuroSci (2014) Flashcards
Describe the piriform cortex and how it is connected to the olfactory bulb.
PC has three layers. Processes door info relayed by OB. OB mitral cell axons form lateral olfactory tract (LOT) by targeting lateral olfactory tract guidepost (lot) cells in PC.
Do lot cells and other PC neurons have pallial or subpallial origin?
Pallial.
When do CR cells differentiate in mouse?
E10.5-E12.5
What are the 3 sites from which CR cells arise in pallial margins?
1) medially, the cortical hem/choroid plexus
2) rostrally, the pallial septum/rostrobulbar area
3) laterally, the ventral pallium
What is Reelin?
A secreted glycoprotein that guides radial migration of neocortical neurons.
Describe the cell types in each of the 3 layers of the PC.
Superficial II and deep III have glutamatergic projection neurons interspersed with GABAergic, layer I is cell-sparse with CR neurons and lot guidepost cells.
Name 4 similarities between lot cells and CR cells.
1) both act as cellular guideposts for axonal tract formation
2) have pallial origin
3) among earliest born cortical neurons
4) migrate tangentially from pallial sites of origin
Ngn1 and Ngn2 are required in two differentiation waves. Describe them.
1) first acting in opposition to control lot cell differentiation (which are a subset of CR neurons, localization depending on Trp73)
2) later controlling differentiation of layer 2/3 PC neurons
At E10.5-E11.5, when CR cells and layer 3 PC cells arise, where do we see Ngn1 and Ngn2 expression?
Scattered pallial progenitors in high lateral to low medial gradient, with transcripts in ventral pallium, cortical hem, and pallial septum.
At E12.5 in CR progenitor domains (pallial septum, ventral pallium, cortical hem) which proneural gene had higher expression?
Ngn2 was expressed in more CR progenitors than Ngn1. However, vast majority of Ngn1+ cells co-expressed Ngn2.
What did short term lineage tracing using Ngn2GFP(KI) show?
At E10.5-15.5: GFP cells in neocortical and piriform cortical marginal zones where CR cells reside. GFP also in germinal zones and mantle layers of neocortex and PC.
