Normal Brain development

Question 1

Role of Laminin in neuronal migration and cortical organisation

Answer 1

1. Integrity of pial basal membrane (λεει στα κύτταρα στοπ)
2. Regulate cell differentiation, migration and adhesion
3. Enhances the ability of oligodendrocytes to form myelin

Question 2

Where is Reelin released?

What is the role of Reelin ?

Answer 2

It is released from Cajal-Retzius cells in marginal zone

1. Regulates neuronal migration and positioning by controling radial glia growth (καλεί τα κύτταρα και τα τοποθετεί)
2. Stimulates dendrite development
3. Adult neurogenesis

Question 3

When does myelination start?

Direction of myelination

Answer 3

28 weeks

• Caudo-cranial
• Postero-anterior
• Centrifugal

Question 4

Describe the abnormalities of CMV in utero early infection under 18 Weeks

Answer 4

Neuronal proliferation will be affected

Microcephaly, cortical malformations, calcifications

Question 5

Describe the abnormalities of CMV in utero early infection 18-24 Weeks

Answer 5

Neuronal migration will be affected

Polymicrogyria, Schizencephaly

Question 6

Describe the abnormalities of CMV in utero late infection >24 weeks

Answer 6

Cortical organisation, myelination will be affected

Cortical abnormalities and leukoencephalopathy

Question 7

Describe the abnormalities of CMV in utero late infection >24 weeks late infection 2

Answer 7

Mostly myelination affected

Leukoencephalopathy and temporal cysts

Question 8

What do BMP and SHH do ?

WNT

Answer 8

Ventral (SHH) - Dorsal (BMP) signaling

Anteroposterior signaling

Question 9

Where is SHH expressed ?

Answer 9

Notochord
Ventral midline of the CNS (except hypothalamic areas)
Endoderm derivatives, Branchial arches, foregut, hindgut,

Question 10

What malformations are associated with SHH misregulation?

Answer 10

Lung (hypoplasia)
Foregut (oesophageal stenosis, atresia)
Limbs (syn polydactyl)
Head (cleft palate, hypotelorism, cyclopia)
CNS (spina bifida , holoprosencephaly)
\+
Tumors (Medulloblastoma)

Question 11

Name two types of progenitor cells migration

Answer 11

*Tangential (GABA-ergic) (inhibitory) interneurons (first)
from germinal zones

*Radial (Glutamete -ergic) (excitatory) neuronal precursors from neocortical germinal zone

Question 12

What is patterning?

Answer 12

Loss of symmetry and development of polarity
Anterior - posterior patterning
Ventral -dorsan patterning

Question 13

role of SHH

Answer 13

Ventral patterning (normal)
Malformations (abnormal)
Tumour genesis (abnormal)

Question 14

3 primary vessicles

Answer 14

Prosencephalon
Mesencephalon
Rhombencephalon

Question 15

Secondary vessicles

Answer 15

Telencephalon + diencephalon
Mesencephalon
Metencephalon + Myelencephalon

Question 16

Metencephalon gives

Answer 16

Pons and cerebellum

Question 17

Diencephalon gives

Answer 17

Thalamus, hypothalamus, epithalamus

Question 18

What is the first stage of cortical development?

Answer 18

Glial proliferation and migration (φτιαχνονται τα κυτταρα πολλαπλασιάζονται και μεταναστεύουν θυμησου σκαλωσιές)

Question 19

Which structure forms the cerebellum?

Answer 19

Upper rhombic lip - rhombomer 1

Question 20

What is the most common type of malformation?

Answer 20

Combined

Question 21

Which radial cells important in gyrification?

Answer 21

Basal radial cells

Question 22

When does brain reach maximum perfusion?

Answer 22

At 24 months of age