Neurodevelopment Flashcards
What germ layers are involved with neuro development
The nervous system develops from ectoderm, but the notochord is of mesodermal origin
Describe the formation of the neural tube
The neural plate rapidly grows and folds inward, eventually fusing at the midline to create a tube that is distinct from the surface ectoderm. The tube closes from the middle with “neuropores” anterior and posterior, which should eventually close.
What are neural crest cells?
Multipotent cells at the edges of the neural folds that differentiate and migrate to form distinct neurons that make up the peripheral nervous system
What are the components of the 3 vesicle stage of neural tube development? “Primary vesicles”
Prosencephalon
Mesencephalon
Rhombencephalon
What are the components of the 5 vesicle stage of neural tube development? “Secondary vesicles”
Telencephalon (cerebral hemispheres) Diencephalon (contains optic vesicle) Mesencephalon (Midbrain) Metencephalon (Pons) Myelencephalon (Medulla)
What are the major flexures seen during early development?
Cephalic (between prosencephalon and rhombencephalon)
Pontine (future cerebellum)
Cervical (Between rhombencephalon and future spinal cord)
What are the communications between the ventricles of the brain?
The foramen of Monro connects the lateral ventricles with the 3rd ventricle. The cerebral aqueduct connects the 3rd and 4th ventricles. The foramen of Luschka lateral) and foramen of Magendie (middle) drain the 4th ventricle.
What are the 3 layers of the neural tube?
Ventricular zone
Mantle layer (grey matter)
Marginal layer (white matter)
*Cells migrate from central canal through ventricular zone, mantle zone and marginal zone
What are the functional differences between the alar plate and basal plate?
Alar: sensory pathways
Basal: motor pathways
In what directions do the dorsal and ventral roots form?
The growth mimics the direction of information:
Ventral root neurons (basal plate) invade adjacent somites, thus growing out of the spine. Dorsal root neurons grow into the alar plate of the spine.
What functional components are contained within the alar plate nuclei? Basal plate nuclei?
Alar plate: Afferents: GSA and GVA
Basal plate: Efferents: GVE and GSE
Describe the location of the basal and alar plate in the medulla
The alar plate becomes lateral and the basal plate is medial
“Motor middle”
Describe the development of the cerebellum
Grows out of the dorsal aspect of the alar plate. The vermis forms from the central region and the cerebellar hemispheres form from the lateral regions. Purkinje cells grow out to form scaffolding for the developing granule cells of the cerebellum.
What are the two major brain structures that form from the diencephalon?
The thalamus and hypothalamus rapidly develop and fill up much of the space of the 3rd ventricle
What is the characteristic shape of all brain structures derived from telencephalon?
C-shaped due to the growth pattern of the telencephalon. As it grows, it wraps up and over the existing brain structures.
