12 - The Ectoderm

What is formed from ectoderm

Neural crest

CNS

Outer surface (epithelial)

Neurulation

Production of the CNS

What is adhesion between cells in the neuroepithelium maintained by

N-cadherin expression

What needs to lose N-cadherin expression

Neural crest cells so that they can migrate

What is different between neural crest cells and neural epithelial cells

Crest = no N-cadherin to become migratory

Epithelial = Express N-cadherin

What do neural crest cells give rise to

Melanocytes

Schwann cells

Peripheral nervous system

Important signalling centres in neurulation

Floor plate and notochord

In head development, what do NC streams form

Frontonasal process

Phalangeal arches

Which region of the brain growth the most during development

Forebrain

What can cause drastic alterations in adult neuroanatomy

Changing patterns of neural progenitor behaviour

Why are some brain regions folded

Increased progenitor formation so large number of neurones

ANR

Anterior neural ridge

MHB

Midbrain-hindbrain boundary

ZLI

Zona limitans inthrathalamica

What do hox genes code for

Transcription factors

What does the homeobox encode

Homeodomain

What does the homeodomain do

Binds to DNA

Transcriptional regulation

How many paralogous Hox clusters in mammals are there

4

What does hox cluster expression control

Identity of hindbrain segments on the AP axis

Where are BMPs/Wnts expressed

Dorsal side

Where is Shh expressed

Ventral side (notochord and floor plate)

Dorsoventral organisation of the spinal chord

Primary sensory neurones

Commissural interneurons

Motor neurones

How many domains of neural progenitor cells are there in neuroepithelial

11

What secretes RA

Adjacent somites

Movement of glutamatergic projection neurones

Follow inside out pattern

Migrate radially from the ventricular zone to the cortical plate

Where are GABAergic interneurons born

Ganglionic eminences

What process do GABAergic interneurons undergo

Tangential migration into the neocortex

How many layers are in the mammalian neocortex

6

What is the neocortex composed of

GABAergic interneurons and inhibitory glutamatergic interneurons

Role of radial glia

Scaffold during development

What secreted reelin

Glial endfeet