Lecture 2: Neural Development Flashcards
What are the three structures of the fetal brain at 3-7 weeks?
Forebrain (Prosencephalon)
Midbrain (Mesencephalon)
Hindbrain (Rhombencephalon)
What does the forebrain turn into?
Cerebral Cortex
What does the notocord cause to happen?
Thickens the neural plate from the ectoderm. Fibroblast growth factor causes the neural plate to turn into spinal cord.
What is derived from the neural fold?
Neural crest cells. They migrate away.
What does the notocord lumen become?
Future ventricles of the brain
What do the cells of the neural tube become?
Future CNS
What do the neural crest cells become?
Future sensory and autonomic ganglia; glial cells
How is secondary neuralation different from primary?
Secondary (caudal, S2 and below) starts from “Mesenchymal to epithelial transition”- The tube forms underneath the epithelium. The primary neurulation happens as the tube zips up.
How are the alar and basal plates situated?
Alar is dorsal, Basal is ventral around the neural tube.
What does the Alar plate become?
Sensory neurons
What does the basal plate become?
Motor neurons
What are the three zones of cells around the notocord?
Germinal/Matrix zone (innermost, has neural stem cells and neuroblasts)
Mantle (has newly born neurons, glia; will become gray matter)
Marginal Zone (outer most; will become white matter with axons) Ependymal Cells line the lumen of the nodal cord, will become CNS
What determines what neural crest cells become?
Location and chemicals in that location
What are neuromeres?
Different segments of the notocord
What does the prosencephalon turn into?
Telencephalon
Diencephalon
What does the mesencephalon turn into?
Mesencephalon
What does the rhomencephalon turn into?
Metencephalon
Myelencephalon
What does the telencephalon turn into?
Lateral ventricles
Cerebrum
Basal ganglia
What does the diencephalon turn into?
Thalamus
hypothalamus
epithalamus
Third ventricle
What does the mesencephalon turn into?
Midbrain
Cerebral aqueduct
What does the metencephalon turn into?
Pons
Cerebellum
Fourth ventricle
What does the myelencephalon turn into?
Medulla oblongata
Fourth ventricle
Where does CSF come from?
Ependymal cells which are covered by pia mater, interior to arachnoid matter. Blood vessels push down into pia mater and ependymal cells. CSF leaks from vessels.
What causes cerebral palsy?
Blood vessels burst in premature infants near lateral ventricle. They can’t control blood pressure in those vessels around upper motor neurons.
Where are viscerosensory cell bodies compared to somatosensory?
Ventrally
How are the neurons situated after the brainstem splits?
Motor is medial, sensory is lateral
What do branchial arches give rise to?
Branchiomotor muscles
Special ear somatosensory
Special taste/olfactory viscerosensory
Where does the cerebellum come from?
Alar plate cells migrate dorsally to the rhombic lip in the pons which came from metencephalon
Where do the vertebrae come from?
Sclerotome cells migrate down and then up and around the neural tube
Where do face bones come from?
Neural crest cells migrate into branchial arches
Where do skull bones come from?
Cells from head somites travel down into branchial arches.
What are dorsal root ganglia made from?
Neural crest cells
Sulcus Limitans
Divids the mantle into basal and alar plates in the spinal cord
Optic vesicle origin
Diencephalon before the anterior neuropore closes
Posterior Pituitary Origin
Midline evagination in floor of forebrain
Pineal Gland Origin
Midline evagination in caudal roof of forebrain
What is the internal capsule?
Bundle of axons heading from the telencephalic cells to the diencephalon, brainstem, and spinal cord.
Corpus Callosum
The lamina terminalis that remains as the connection between the two cerebral hemispheres
