Class 3, Chapter 23 - Development

Question 1

Postnatal brain growth is due to

Answer 1

differentiation, mylenation, growth of EXISTING neurons

Question 2

How many cells are made per minute during prenatal development?

Answer 2

250,000 cells

Question 3

What are the two stages of CNS development?

Answer 3

Prenatal development (structural formation, genetically determined) and postnatal development (susceptible to environmental influences)

Question 4

What are the two opposing developmental processes?

Answer 4

Additive development (myelination, dendritic arborization). Regressive processes (apoptosis, synaptic pruning)

Question 5

When is the embryonic period? And what is formed in general?

Answer 5

Conception to 8 weeks. Rudimentary CNS structures made

Question 6

When is the fetal period? And what is formed, in general?

Answer 6

9 weeks to birth. Rapid cortical and subcortical structure growth

Question 7

What produces neural stem cells through the creation of 3 tissue layers?

Answer 7

Gastrulation

Question 8

What layer from the embryonic disc results in the CNS?

Answer 8

Ectoderm

Question 9

When and how does the neural tube develop?

Answer 9

Develops by week 4 of gestation. Gastrulation of ectoderm > neural plate forms > neural groove from folding > neural tube

Question 10

What is the process of forming the neural tube called? When does it happen?

Answer 10

Neurolation (2nd and 4th week gestation)

Question 11

What are the three vesicles that form at the anterior end of the neural tube?

Answer 11

Prosencephalic (forebrain), mesencephalic (midbrain), rhombencephalic (hindbrain)

Question 12

What happens in the 5th week of gestation?

Answer 12

Prosencephalic vesicle becomes telencephalon and diencephalon. Rhombencephalic vesicle becomes metencephalon and mylencephalon.

Question 13

What happens in the 7th week of gestation?

Answer 13

Telencephalon becomes cerebral hemispheres. Diencephalon divides into thalamus. Myelencephalon becomes medulla. Metencephalon becomes cerebellum and pons.

Question 14

What are the 7 stages of brain development?

Answer 14

1. Cell birth
2. Cell migration
3. Cell differentiation
4. Cell maturation
5. Synaptogenesis
6. Cell death and synaptic pruning
7. Myelogenesis

Question 15

What is nerve cell production called and where and when does it happen?

Answer 15

Neurogenesis within the neural tube and starts at 40 days gestation

Question 16

What is cell migration guided by?

Answer 16

Radial glial cells

Question 17

When does cell migration happen?

Answer 17

Fetal week 8 to week 16

Question 18

What is dendritic arborization?

Answer 18

Growth of dendritic spines that continues after birth

Question 19

What is synaptogenesis?

Answer 19

Development of axons

Question 20

What is synaptic pruning?

Answer 20

Neurons that don’t make good connections undergo apoptosis. Up to 50% will DIE :(

Question 21

What are the three synaptogenic processes?

Answer 21

Experience independant (will always happen)
Experience expectant (need environmental cues to happen)
Experience dependant (development that is personal/unique to a species)

Question 22

As we age, synaptic density _____

Answer 22

Decreases

Question 23

Where does postnatal myelination start and end?

Answer 23

Starts at spinal cord, ends at telencephalon/diencephalon

Question 24

What do animal models tell us about brain development?

Answer 24

Complex environments increase brain growth. Old/young brains respond differently to experiences

Question 25

Musicians who use their left hand to play violin have ____?

Answer 25

Larger representation for their fingers on their brain

Question 26

What do imaging studies tell us about brain development? (In terms of grey and white matter volume)

Answer 26

Grey matter decreases, white matter increases. Cortical thickness and SA both decrease.

Question 27

What does "small world" mean in the context of brain networks?

Answer 27

Neurons are lazy, they will make the most efficient connections possible and stay local

Question 28

What are salience, executive function and default mode networks in the brain?

Answer 28

Salience = readiness/motivation to act in response something Executive function = planning, thinking, being humans Default mode = not doing anything

Question 29

What are the three types of functional brain development?

Answer 29

``` Maturation (brain structures mature and behaviors mature) Skill learning (you activate brain regions when you learn things and your brain becomes better) Interactive specialization (cortical regions interact with each other and acquire certain roles) ```

Question 30

Why are teens impulsive and dumb?

Answer 30

Their emotional response in striatum is not well modulated by their inhibition response in the frontal cortex

Question 31

ADHD is characterized by what structural brain changes?

Answer 31

Decreased brain volume

Question 32

Does the brain grow uniformly?

Answer 32

No, the brain increases in mass in growth spurts

Question 33

What matures faster, the basal ganglia or temporal lobe?

Answer 33

Basal ganglia as shown by nonmatching-to-sample and concurrent discrimination tasks

Question 34

What happened to the Romanian orphans?

Answer 34

Their shitty orphan conditions gave them developmental delay and lower than average IQ

Question 35

What did studies where vision of kittens were restricted suggest?

Answer 35

The visual system can lose capacity if not exercised during early months of life