Wiring of the Brain: Axonal Guidance & Target Selection

Question 1

Improper neuronal migration is implicated in

Answer 1

Schizophrenia

Question 2

Role of Guide Post Cells (GPC)

Answer 2

Axonal guidance and direction change

Question 3

NT used by GPC

Answer 3

GABA

Question 4

GPC of hippocampus

Answer 4

Cajal-retzius

Question 5

GPC of cortex

Answer 5

Subplate

Question 6

Role of Pioneer Neurons

Answer 6

Specialized cells acitvated in the developing CNS (first ones)

Question 7

What are the primary sensory cells (pioneer cells) of the developing spinal cord

Answer 7

Rohon-Beard neurons

Question 8

What part of the neuron is implicated in pathfinding

Answer 8

Growth cone

Question 9

What is the growth cone made out of

Answer 9

Lameelliopodia

Question 10

What do growth cones eventually differentiate into?

Answer 10

Presynaptic terminal

Question 11

Trophic molecules

Answer 11

Growth and survival )

Question 12

Tropic molecules

Answer 12

Guidance

Question 13

Name 3 types of extracellular growth molecules

Answer 13

1. Extracellular Matrix Molecules
2. Cell Adhesion Molcules & Cadherins
3. Soluble chemoattractants and repellants

Question 14

Which Ca dependent or independent between Cell Adhesion Molcules & Cadherins

Answer 14

Cell Adhesion Molecules: Ca independent

Cadherins: Ca dependent

Question 15

Name the partner

SLIT

Answer 15

ROBO

Question 16

Name the partner

Ephrins

Answer 16

Ephs

Question 17

Name the partner

Netrin

Answer 17

DCC

Question 18

Semaphorin

Answer 18

Neuropilins & plexins

Question 19

Neutrophins

Answer 19

Trks

Question 20

In the developing retina, what molecule causes direction change at optic disc

Answer 20

Netrin - DCC

Question 21

What molecule is important for optic stalk formation?

Answer 21

Seaphorin

Question 22

What molecules are important for optic chiasm development? What happens to their concentration

Answer 22

Shh ↓
NCAMS & Sema 3D
Wphrin B2 & EphB

Question 23

What molecules (2) moves axons from chiasm to tracts?

Answer 23

GAP43 & Cadherins & integrins

Question 24

What molecule prevents crossing into di/telencephahlon?

Answer 24

CSPG

Question 25

What molecules prevent axons from going a stray

Answer 25

Slit - Robo

Question 26

What molecule is important for telling the growing axon that it has reached its target? At what concentration

Answer 26

Fibroblast Growth Factor - lowest at target (superior colliculus for the eye)

Question 27

What type of gradients establish retinotropic maps

Answer 27

Invers gradients of EphA/EphrinA and EphB/EphrinB

Question 28

The ventral retina has the most EphB so projects to the

The dorsal retina has the least Eph B so projects to the

Answer 28

Lateral SC which has the lowest Ephrin B

Medial SC which has the most Ephrin B

Question 29

The temporal retina has the most EphA so projects to the

The nasal retina has the least EphA so projects to the

Answer 29

Anterior SC which has the least Ephrin A

Posterior SC which has the most Ephrin A

Question 30

Benefits of gradients (2)

Answer 30

1. Dimensional specifictiy

2. lasticity

Question 31

Define neural refinement

Answer 31

Redundancy after intial development is removed by activity pattens (neurons the fire together) wire together