Development And Plasticity

Question 1

When does the nervous system begin to form for an embryo>

Answer 1

2wks

Question 2

How much does the brain weigh at birth?

Answer 2

350g

Question 3

First year how much does brain weight

Answer 3

1000g

Question 4

How much does the adult brain weigh

Answer 4

1200-1400g

Question 5

Proliferation

Answer 5

Production of new cells/neurons in brain

Question 6

migration

Answer 6

Movement of newly formed neurons and glia to location

Question 7

T/F some neurons dont reach their location until adulthood

Answer 7

True

Question 8

How does migration happen?

Answer 8

Follow chemical paths

Question 9

Differentiation

Answer 9

Forming of axon and dendrite that gives neuron its shape

Question 10

What part of the neuron grows first? When?

Answer 10

Axon
During migration/when it reaches target

Question 11

When do dendrites develop

Answer 11

After axon

Question 12

Where does myelination first occur

Answer 12

Spinal cord

Question 13

Synaptogenesis? When does it occur?

Answer 13

Formation of synapses between neurons
Constantly forming and discarding old ones

Question 14

Stem cells

Answer 14

Undifferentiated cells that generate daughter cells that can transform into glia or neurons

Question 15

What do stem cells differentiate into?

Answer 15

New neurons in the hippocampus

Question 16

Do mammalian cerebral cortexes form new neurons after birth?

Answer 16

No

Question 17

How do axons reach their target areas?

Answer 17

Following a gradient of chemicals- more attracted to some chemicals and repelled by others

Question 18

Strengthen connections with some cells and eliminate connections w others

Answer 18

Postsynaptic cells

Question 19

What controls the formation or elimination of connections?

Answer 19

Inputs from incoming axons

Question 20

Neural Darwinism

Answer 20

Initially form more connections than we need
Most successful connections survive

Question 21

Nerve growth factor

Answer 21

Promotes survival and growth of axons

Question 22

How does the brain’s system enable exact matching of number of incoming axons to number of receiving cells

Answer 22

Apoptosis

Question 23

Neurotropin

Answer 23

Chemical that promotes neuron survival

Question 24

Why is the visual cortex thicker on blind people?

Answer 24

Lack of stimuli; cannot prune out ineffective neurons

Question 25

Chemical distortions in brain during development can cause

Answer 25

Impairment and developmental problems

Question 26

Fetal alcohol syndrome

Answer 26

Mother drinks heavily during pregnancy

Question 27

What are the dendrites like in children with fetal alcohol syndrome?

Answer 27

Short

Question 28

What does alcohol in the fetus brain suppress and enhance? What does this cause

Answer 28

Glutamate Release of GABA Less excitation, more apoptosis

Question 29

Smoked cigarettes

Answer 29

Risk for ADHD

Question 30

What do antidepressants during pregnancy increase the risk of

Answer 30

Heart problems

Question 31

________ neurons transplanted to a ______ part of the cortex develop the properties of the new location

Answer 31

Immature Developing

Question 32

neurons transplanted at a _____ stage of development develop some new but retain some old properties

Answer 32

Later

Question 33

How does fine-tuning work?

Answer 33

Dendrites continue to modify structure and connections through life time Dendrites continually grow new spines

Question 34

Rats raised in an _______ environment develop a _____ cortex and _______ dendritic branching

Answer 34

Enriched Thicker Incr

Question 35

What helps expansion of neurons

Answer 35

Physical activity

Question 36

Closed head injury

Answer 36

Sharp blow to head that does not puncture brain

Question 37

Stroke

Answer 37

Temporary loss of blood flow to brain

Question 38

Ischemia

Answer 38

Blood clot that causes neurons to lose oxygen and glucose supplu

Question 39

Excitoxiticity

Answer 39

Neurons flooded with excess blood, calcium, oxygen, and other chemicals

Question 40

Edema

Answer 40

Accumulation of fluid in brain resulting in increased pressure

Question 41

Diaschisis

Answer 41

Decreased activity of surviving neurons after damage to other neurons

Question 42

Cell bodies cannot be ____ but axons do _____

Answer 42

Replaced Grow back

Question 43

Damaged axons only regenerate ______ mm

Answer 43

1-2

Question 44

Denerviation supersensitivity

Answer 44

Heightened sensitivity to neurotransmitter after the destruction of incoming axon

Question 45

Phantom limb

Answer 45

Continuation of sensation of amputated body part

Question 46

Collateral sprouts

Answer 46

New branches formed by other non damaged axons that attach to vacant receptors

Question 47

Autism has ____ paths

Answer 47

Multiple

Question 48

What does brain development in autistic children

Answer 48

Larger, but areas are under activated Later period of degeneration