NEU 202 Development

Reelin

Released by Cajal-Retzius cells, signals other cells to stop radial migration; important for process of lamination

Lamination

Process by which neurons form layers in the developing brain, mediated by Cajal-Retzius cells

Newest cells are furthest out

Ganglionic Eminences

Two centers that develop in ventral telencephalon around the end of the 5th week of gestation

GABAergic inhibitory neurons develop in medial _______ ________

Tangential migration

Neurons migrate in a lateral manner

Radial migration

Neurons migrate outward; spokes on a wheel

Intrinsic factors

"Lineage factors”

Extrinsic factors

“Neighbor factors”

Pluripotency

The ability for a cell to become any one of many different cell types → stem cells

Fate determination

Process by which unspecialized stem cells commit to becoming specific types of mature neurons/glial cells

Differentiation

Irreversible process of becoming a specific cell type

Factors

Gene products specifically expressed in specific cell types

Migration

Movement of cells to create microscopic/macroscopic structures

Patterning

establishment of distinctly organized structural and functional areas

Neuroectodermal

_____________ stem cells will become the nervous system

Neuroectoderm

____________ forms within the medial region of the ectoderm and forms the neural plate; process is coordinated by the notochord

Microglia

Originate from yolk sac cells, more closely related to immune macrophages

Neurulation

Forms neural groove around third week of gestation; process of invagination = fold in neural plate

Neural crest

Gives rise to sensory and autonomic ganglia (major elements of peripheral nervous system)

Neural tube

Gives rise to spinal cord

Anterior neural folds

Anterior ends of neural plate grow together at midline and eventually give rise to the brain

Neuropores

Last two parts of the neural tube to close are the anterior and posterior ________

Spina bifida

Posterior failure of neuropore to close, leads to defects in formation of portions of spinal column and spinal cord

Ancephaly

Anterior failure of neuropore to close, leads to defects in formation of parts of brain and skull

Neural progenitors

Cells that will become neurons

CNS

____ will emerge from neural tube

PNS

___will emerge from neural crest

Cranial, Vagal, Trunk, Sacral

4 populations of neural crest cells

Embryonic period

period that lasts through week nine of gestation

Fetal period

period that begins after embryonic period and lasts until birth

Prosencephalon

Mesencephalon

Rombencephalon

Telencephalon

diencephalon

Metencephalon

Myelencephalon

Patterning

process by which distinct regions or domains form within the developing embryo

Hox genes

Sequential expression of __ ____ leads to segmented patterning in animal development

Gradients

________ of signaling affect many cells in an area

Symmetric division

Neural precursor cells in ventricular zone of neural tube create two new stem cells through ________ ________

Asymmetric division

Occurs around E45, cell divisions create a neuroblast and neural progenitor cell

telencephalon, diencephalon

The prosencephalon forms the ___________ and the _____________

mesencephalon

the ____________ remains

metencephalon, myelencephalon

the _________ and ____________ develop from the rhombencephalon

Post mitotic

____ ______ neuroblasts move away from the ventricular zone

somal translocation

small radial movement through the neural tube → process to pial surface, moves as process shrinks

Subventricular zone

New glia originate in the forebrain ______________ ________

epiblast

the _____ will form all the structures of the developing embryo

hypoblast

the ________ will form the placenta and connection stalk

Cranial

_______ neural crest forms teeth, thyroid, skull, sensory ganglia

Vagal

_______ neural crest forms enteric nervous system

Trunk

____ neural crest forms dorsal root ganglia (sensory PNS)

Sacral

_____ neural crest forms additional enteric neurons + sympathetic ns

cortical plate

receives migrating neurons to start lamination

radial glia

guide cortex migration

bergmann glia

guide cerebellum migration

Ventricular zone

Neural precursor cells are located in the _______ ___

stem cell, neuroprogenitor

Asymmetric division creates a ____ ____ and _________