Fxn Neuro Lec 39 - Neuroembryology

Front 1

The lamina terminalis represents:

Back 1

the site of cranial neuropore closure

Front 2

Neural folds and Neural groove together comprise the:

Back 2

neuroectoderm

Front 3

Why do cleft palates occur?

Back 3

failure of rostral neural crest cells to migrate normally

Front 4

Congenital Megacolon aka Hirshprung’s disease is due to:

Back 4

failure of some parasympathetic precursors to migrate normally

Front 5

During neural tube development, what will eventually give rise to all of the neurons and macroglia of the nervous system?

Back 5

neuroepithelial cells that comprise the ventricular zone of the neural tube

Front 6

Because neurons develop from neuroblasts which have lost the ability to divide, most brain tumors arise from:

Back 6

glial cells and meningeal cells which can still divide throughout life

Front 7

What gives rise to the spinal cord ventral horn including GVE and GSE neurons?

Back 7

basal plates: anterior cellular thickenings within the mantle zone of the spinal cord

Front 8

What give rise to the spinal cord dorsal horn?

Back 8

alar plates

Front 9

What marks the junction of the alar and basal plates?

Back 9

the sulcus limitans

Front 10

During spinal cord development, the marginal zone becomes:

Back 10

the white matter of the cord

Front 11

What demarcates the junction of the spinal and hindbrain?

Back 11

Cervical flexure

Front 12

What flexure occurs between the hindbrain and midbrain?

Back 12

Cephalic flexure

Front 13

What are both flexures associated with?

Back 13

“head fold” both are concave ventrally

Front 14

What is the Cerebellum derived from?

Back 14

Rhombic lips of the metencephalic alar plate

Front 15

What structures derive from the Diencephalon?

Back 15

THOR GISE: Thalamus, Hypothalamus, Optic Nerves, Retina,Globus Pallidus, Infundibulum, Subthalamic nucleus, Epithalamus and pineal gland.

Front 16

The neurohypophysis is derived from:

Back 16

Rathke’s pouch: an ectodermal diverticulum of the stomodeum

Front 17

During differentiation of the Telencephalon the most medial part of the pallium (archipallium) becomes:

Back 17

hippocampus and dentate gyrus

Front 18

The most lateral part of the pallium (paleopallium)becomes:

Back 18

parahippocampal gyrus

Front 19

The large central zone of the pallium (neopalium) becomes:

Back 19

the major part of the cortex

Front 20

How do neuroblasts move during cerebral cortex development?

Back 20

neuroblasts from the ventricular zone migrate outward to form an intermediate zone

Front 21

Why would neuroblast migration during cerebral cortex development be described as “inside-out”

Back 21

deep layers arrive in the cortical plate first, and more superficial layers migrate outward past them

Front 22

Failure of the cortical neuroblasts to migrate properly can lead to:

Back 22

gross cerebral deformities such as agyria or pachygria. also occurs in epilepsy and autism

Front 23

Describe Anencephaly

Back 23

absent skull, brain, and cranium

Front 24

Describe Encephalocoele

Back 24

sac-like protrusion of the meninges and brain from the head

Front 25

Define Rachyschisis

Back 25

wide open splaying of the spinal cord

Front 26

Describe Spina Bifida

Back 26

isolated opening of the spinal cord, with protrusion of and the meninges and/or spinal cord structures

Front 27

How common are neural tube defects (NTD)?

Back 27

1-2/1000 live births

Front 28

How are NTDs tested for?

Back 28

Measurement of maternal serum alpha feto-protein in the blood at 15-20 weeks gestation

Front 29

Neural tube defects are classified as what type of genetic disorder?

Back 29

Multifactorial

Front 30

What are some maternal medication exposures are linked to NTDs?

Back 30

Anti-epileptic drugs, Aminopterin, Vitamin A, Isoretinoin

Front 31

The terminal cranial opening of the neural tube is called the:

Back 31

neuropore

Front 32

Failure of the cranial neuropore to close leads to:

Back 32

Anencephaly

Front 33

Failure of the caudal neuropore to close leads to:

Back 33

Spina bifida

Front 34

Sonic Hedgehog expression is involved in several developmental steps:

Back 34

1. leads to overgrowth of ectoderm on the top of the notocord, 2. pushes the neural tube ventrally, 3. keeps structures oriented ventrally by inhibiting overlying transcription factors

Front 35

Sonic hedgehog also acts through positive regulation of another protein:

Back 35

patched 1 (ptc 1)

Front 36

What happens when SHH binds to ptc?

Back 36

the transmembrane receptor called smoothened is not longer inhibited by ptc and smoothened can then activate another gene product GLI which then acts as a transcriptional activator

Front 37

What two things do BMP 4 and 7 do?

Back 37

1. maintain growth dorsally to form the roof of the neural tube, 2. established the dorsal orientation of the neural tube

Front 38

Why is it difficult to get NTDs in knock-out mice?

Back 38

there is not one causative gene but multiple polygenic effects influenced by a variety of environmental factors

Front 39

How do we know that folic acid is important for neural tube development?

Back 39

expression of folate receptors is elevated during neural tube closure

Front 40

What is the active form of folic acid?

Back 40

tetrahydrofolic acid

Front 41

Defects of what gene can lead to severe neurologic impairment?

Back 41

MTHFR methylene tetrahydrofolate reductase