Neuronal Migration Synapse Formation and Survival

Question 1

How do we get from a tube to the highly developed nervous system

Answer 1

Neuronal migration and axon guidance

Question 2

True or False:

Wiring up the brain is a simple process

Answer 2

False

Question 3

True or False:

Distance is a contributing factor of difficulty in the developing nervous system

Answer 3

True

Question 4

What is a receptive field

Answer 4

The area that a receptor is able to respond to a stimuli

Question 5

What stretch as the nervous system expands

Answer 5

Pioneer axons

Question 6

How do the axons know where to grow

Answer 6

They follow chemical cues

Question 7

True or False:

Pioneer axons guide neighboring axons

Answer 7

True

Question 8

How many neurons in a new born and an adult

Answer 8

New born 300 billion

Adult 80 billion

Question 9

True or False:

Each neuron has a single phenotype and one or a few neurotransmitters

Answer 9

True

Question 10

One neuron can have how many synapses

Answer 10

700-1500

Question 11

What maintain contact with the inner and outer edges of the wall of the neural tube

Answer 11

Radial glial cells

Question 12

Where do cells proliferate in

Answer 12

The ventricular zone

Question 13

Where do cells migrate into

Answer 13

The mantle zone

Question 14

What does the mantle zone form

Answer 14

Gray matter

Question 15

What do neurons travel along to get to their end resting place

Answer 15

Radial glial cells

Question 16

Where do axons go as they move out from the cells

Answer 16

The marginal zone

Question 17

What does the marginal zone form

Answer 17

White matter

Question 18

True or False:

The mantle zone becomes most of the brain and cord

Answer 18

True

Question 19

What is the key element responsible for the growth of an axons and dendrites toward its target

Answer 19

The growth cone

Question 20

What is actin that collects at the surface of the growth cone called

Answer 20

Filopodia

Question 21

What do filopodia do

Answer 21

Creep forward and grab onto the surface pulling the growth cone with it

Question 22

What are the 3 main domains of the growth cone

Answer 22

1. Central core
2. Lamellipodium
3. Filopodium

Question 23

True or False:

The growth cone contains sensory structures to guide it by chemical cues

Answer 23

True

Question 24

What are the motile domains of the growth cone

Answer 24

1. Filopodium

2. Lamellipodium

Question 25

What is the gradient effect

Answer 25

Chemical cues change in concentration so the growth cone knows which direction to head.

Question 26

In the spinal cord what are the only remnants of the ventricular zone

Answer 26

Ependymal cells

Question 27

True or False: | Radial glia maintain connections to the very surface of the cerebral cortex for a long time

Answer 27

True

Question 28

How do the cells migrate in the cerebral cortex

Answer 28

The new cell goes behind the last cell that was laid down

Question 29

In the cerebral cortex where are the youngest and oldest cells located

Answer 29

Youngest are superficial | Oldest are deepest

Question 30

How many waves of neuronal migration occur in the cerebral cortex

Answer 30

6

Question 31

What is a very protracted developmental process that starts during early brain development and continues through life

Answer 31

Synaptogenesis

Question 32

Why is synapse elimination important

Answer 32

Because there are many more synapses formed than will be present in the adult animal

Question 33

What are the 2 types of projection errors in migration

Answer 33

1. Axons may project to the correct target but they may spread out too far (lack of precision or overshooting) 2. Postsynaptic neuron or target receives inputs from the wrong number of afferents

Question 34

What does myelin allow for

Answer 34

A reduced need for more cells

Question 35

What are the 3 cells of the synapse

Answer 35

1. Motor neuron 2. Myofiber 3. Schwann cell

Question 36

What are the 3 steps in the formation of a CNS synapse

Answer 36

1. Dendritic filopodium contacts axon 2. Synaptic vesicles and active zone proteins are recruited to presynaptic membrane 3. Receptors accumulate on postsynaptic membrane

Question 37

What helps the development of brain function

Answer 37

Balance between genesis and elimination of cells and synapses

Question 38

What is apoptosis

Answer 38

Programmed cell death

Question 39

What does apoptosis do

Answer 39

Rapidly removes cells

Question 40

Is apoptosis an inflammatory process

Answer 40

No

Question 41

Throughout development of the human nervous system how many neurons may die regionally

Answer 41

More than half

Question 42

About how many of the neurons die off that were present at birth

Answer 42

2/3

Question 43

True or False: | The amount of neuron death varies across species

Answer 43

True

Question 44

True or False: | Some neurotrophic factors block default apoptosis

Answer 44

True

Question 45

What are 2 examples of diseases involving neurotrophic factors

Answer 45

1. Huntingtons chorea | 2. Parkinsons

Question 46

What is huntingtons chorea

Answer 46

Loss of huntington protein which upregulates BDNF and the survival of striatum neurons

Question 47

What is parkinsons disease

Answer 47

Death of dopaminergic neurons which repsond to Glial dopamine neuronal factor (GDNF) and Cortical DNF (CDNF)

Question 48

What controls movement in utero

Answer 48

Midbrain because it is not conscious

Question 49

True or False: | Synaptic changes occur throughout life

Answer 49

True

Question 50

What is synaptic plasticity dependent on (5)

Answer 50

1. Learning 2. Experiences 3. Environment 4. Lifestyle 5. Health

Question 51

True or False: | Once the brain is developed plasticity decreases with age

Answer 51

True