Neuronal Migration Synapse Formation and Survival Flashcards Preview

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Flashcards in Neuronal Migration Synapse Formation and Survival Deck (51)
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1
Q

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

A

Neuronal migration and axon guidance

2
Q

True or False:

Wiring up the brain is a simple process

A

False

3
Q

True or False:

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

A

True

4
Q

What is a receptive field

A

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

5
Q

What stretch as the nervous system expands

A

Pioneer axons

6
Q

How do the axons know where to grow

A

They follow chemical cues

7
Q

True or False:

Pioneer axons guide neighboring axons

A

True

8
Q

How many neurons in a new born and an adult

A

New born 300 billion

Adult 80 billion

9
Q

True or False:

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

A

True

10
Q

One neuron can have how many synapses

A

700-1500

11
Q

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

A

Radial glial cells

12
Q

Where do cells proliferate in

A

The ventricular zone

13
Q

Where do cells migrate into

A

The mantle zone

14
Q

What does the mantle zone form

A

Gray matter

15
Q

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

A

Radial glial cells

16
Q

Where do axons go as they move out from the cells

A

The marginal zone

17
Q

What does the marginal zone form

A

White matter

18
Q

True or False:

The mantle zone becomes most of the brain and cord

A

True

19
Q

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

A

The growth cone

20
Q

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

A

Filopodia

21
Q

What do filopodia do

A

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

22
Q

What are the 3 main domains of the growth cone

A
  1. Central core
  2. Lamellipodium
  3. Filopodium
23
Q

True or False:

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

A

True

24
Q

What are the motile domains of the growth cone

A
  1. Filopodium

2. Lamellipodium

25
Q

What is the gradient effect

A

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

26
Q

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

A

Ependymal cells

27
Q

True or False:

Radial glia maintain connections to the very surface of the cerebral cortex for a long time

A

True

28
Q

How do the cells migrate in the cerebral cortex

A

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

29
Q

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

A

Youngest are superficial

Oldest are deepest

30
Q

How many waves of neuronal migration occur in the cerebral cortex

A

6

31
Q

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

A

Synaptogenesis

32
Q

Why is synapse elimination important

A

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

33
Q

What are the 2 types of projection errors in migration

A
  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
34
Q

What does myelin allow for

A

A reduced need for more cells

35
Q

What are the 3 cells of the synapse

A
  1. Motor neuron
  2. Myofiber
  3. Schwann cell
36
Q

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

A
  1. Dendritic filopodium contacts axon
  2. Synaptic vesicles and active zone proteins are recruited to presynaptic membrane
  3. Receptors accumulate on postsynaptic membrane
37
Q

What helps the development of brain function

A

Balance between genesis and elimination of cells and synapses

38
Q

What is apoptosis

A

Programmed cell death

39
Q

What does apoptosis do

A

Rapidly removes cells

40
Q

Is apoptosis an inflammatory process

A

No

41
Q

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

A

More than half

42
Q

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

A

2/3

43
Q

True or False:

The amount of neuron death varies across species

A

True

44
Q

True or False:

Some neurotrophic factors block default apoptosis

A

True

45
Q

What are 2 examples of diseases involving neurotrophic factors

A
  1. Huntingtons chorea

2. Parkinsons

46
Q

What is huntingtons chorea

A

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

47
Q

What is parkinsons disease

A

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

48
Q

What controls movement in utero

A

Midbrain because it is not conscious

49
Q

True or False:

Synaptic changes occur throughout life

A

True

50
Q

What is synaptic plasticity dependent on (5)

A
  1. Learning
  2. Experiences
  3. Environment
  4. Lifestyle
  5. Health
51
Q

True or False:

Once the brain is developed plasticity decreases with age

A

True