Ch. 13, Development

Question 1

three perspectives on brain development

Answer 1

1. structural brain developmnet = predicts behavior
2. Behavior = predicts structural brain development
3. Other factors are more important: SES, hormones,etc which can all influence brain developmnent

Question 2

Major findings from research on brain development and SES

Answer 2

Noble 2015 =
1. Lower family income = decreased cortical surface area across frontal, temporal and parietal lobes
2. Worse cognitive perfrormance across language and memory domains

Question 3

Tower of hanoi, what it tests, profiency ages

Answer 3

tests planning = tests frontal lobe development
age 10: can do very simple forms of this task
age 15-17 can do much more complex versions of the task

Question 4

Preformation idea in the 1800s

Answer 4

scientists used to believe that sperm and egg cells had tiny humans that just grew up in the womb
reality: embryos look nothing likle adults they become

Question 5

What supports Darwin’s idea of common ancestry?

Answer 5

that embryos of diff species more closely resemble each other than their parents= supports darwin’s view

Question 6

Period of zygote, em,bryo, and fetus

Answer 6

Zygote: conception to 2 weeks
embryo: 2 weeks-8 weeks
fetus: 9 weeks–birth

Question 7

what is the three chambered brain and when is it visibnle in humans?

Answer 7

visible at day 28
includes forebrain, midbrain, hindbrain

Question 8

Fetal terms for the forebrain, midbrain, and hindbrain

Answer 8

Prosencephalon = will become forebrain
Mesencephalon= will become midbrain
Thombencephalon = will become hindbrain

Mesencephalon + thombencephalon = brainstem

Question 9

Formation of the neural tube process

Answer 9

1. Outermost layer of the embryonic disk becomes thicker
2. Forms the neural plate: primitive neural tissue that develops
3. = forms the neural tube, a structure in early development from which the brain and spinal cord arise; nursery of cells for the entire CNS

Question 10

What day is the neural tube developed and what happens if it is defective?

Answer 10

24 days
neural tube = nursery of cells for the entire CNS
if it doesn’t close fully = spinal cord defects

Question 11

Teratogens and timing

Answer 11

earlier the terotogen = worse timing
“Safest” time to have terotagen: between 6-8 weeks, because migration of the cells hasnt occured yet but b

Question 12

Anterior vs posterior part of the neural tube

Answer 12

anterior= beomes the spinal cord
posterior = becomes the brain

Question 13

3 stages of prenatal brain development

Answer 13

1. C ell birth (includes neurogenesius and glialgensis)
2. Neural migratioin: cells move to specific brain locations
3. Differentiation: have to form particular type of cell

Question 14

4 stages of brain development that occur AFTER BIRTH

Answer 14

4. Neural maturation (growth of dendrite and axons)
   5., Synaptogensis/forming synapses
5. Synpatic pruning
6. Myelogenosis (formation of myelin) up until age 25-30

Question 15

ESCs

Answer 15

embryonic stem cells: can become any cell in the embroyo/most unspecialized type

Question 16

Requirements for a cell to be a stem cell

Answer 16

1. Must be able to reproduce itself indefinetly
2. Differentiate into more than ONE type of specialized cell

Question 17

symmetrical vs asymmetrical division of stem cells

Answer 17

symmetrical: one stem cell – produces two stem cells
asymmetrical: one stem cell – produces one stem cell and onew other type of precurser/progenitor cell – which then divides into further cells

Question 18

4 types of stem cells from most general to most specific

Answer 18

1. Totipotent: omnipotent, do everything, most unspecialized, can give rise to embyronic cells and placenta cells, INCLUDES ZYGOTE AND CELLS OF FIRST 2 DIVISIONS
2. Pluripotent: can differentiate into all embryonic cells, BUT NOT placenta cells (embryonic stem cells, ESCS)
3. Multipotent: can differentiate into multiple specialized cell types found in specific tissues/organs (neural stem cells) but still MULTIPLE TYPES OF CELLS
4. Unipotent: single lineage, example: spermatogonial stem cells, can reproduce indefinetly but only as sperm cells

PUMT

Question 19

Progenitor cell/percursor cell/ neuroblast/glioblast

Answer 19

progenitor/precursor: cell derives from a stem cell that migrates and produced a neuron or glial cell
neuroblast: product of the progenitor cell = then gives rise to diff types of neurons
glioblast: product of a progenitor cell = gives rise to diff types of glial cells

Question 20

start of neurogensis, differentiation, migration

Answer 20

Neurogenesis 6-25 wks
Migration and Differentiation: 8 - 29 weeks.
Maturation (green bar/green numbers). 20 wks - after birth

Question 21

Paternal FASD

Answer 21

pre-conception drinking of the father can create FASD = sperm are continously developing and can get harmed in this process

Question 22

radial glia

Answer 22

type of neural stem cell (NSC) self renews, produces all different types of neurons

Question 23

subventricular zone in fetal brain

Answer 23

contains a lining of all NSCs: contains map of cortex to be able to direct neurons to where they should go in the brain

Question 24

4 steps of cell differentiation

Answer 24

1. Uncomitted precursor (like a NSC)
2. Cells with some segregation of determinants (progenitor)
3. further segregation of determinations
4. influenced by intercellular environmernt
   = diverse cells

Question 25

two types of signals that specify cell fate

Answer 25

intrinsic: inherited from mother cell extrinsic: chemical cues from cell's surroundings

Question 26

function of radial glial cells in migration

Answer 26

1. Radial glia have 2 general functions. They are neural stem cells 2. They also act like a path-finding scaffold, allowing the migrating neuroblasts (their daughter cells) to migrate from the ventricular surface, all the way up to the cortical surface. The immature neurons "climb" up the radial glia cells as they are migrating. 

Question 27

difference between stem cells and progenitor cells

Answer 27

progenitor cells can only divide a limited number of times, not indefinitely progenitor cells can only divide into their target cells, much more specialized than stem cells

Question 28

Two types of neural maturation and their rates (stage 4)

Answer 28

1. dendritic growth: OCCURS MUCH SLOWER, rate of microns/per day, provide surface area for synapses with other cells Arborization= slow growth 2. Axonal extension: VERY FAST, mm/per day, presynaptic guide the development of postsynaptic terminals, extend toi targets in order to intitiate synapse formation 1000 times faster than dendritic growth -MAJORITY OF MATURATION HAPPENS AFTER BIRTH BUT BEGINS AT 20 WEEKS PRENATALLY

Question 29

ASD symptoms, rate, gender difference

Answer 29

1. impaired social interaction 2. restricted range of interests 3. robotic tone/abnormal communication skills 4. repetitive movements 1/54 children more severe and 4x more prevalen t in boys: no reason known as to why

Question 30

Neural causes of ASD

Answer 30

neuronal maturation that occurs TOO FASt = too much brain volume in the F-A-T: frontal, amygdala, and temporal lobes, as well as cerebellum (responsible for social and motor correction)

Question 31

girls vs boys in ASD brain volume

Answer 31

girls, age 7: TD and ASD children gray matter volumes are equal boys: age 13, gray matter volumes betwqeen TD AND ASD have still not equaled out

Question 32

Santiago Cajal and growth cones

Answer 32

proposed the idea of growth cones: guide the growth of axons

Question 33

Filopedia vs lamellipodium

Answer 33

filopedium/pedia: finger-like projections, constantly growing/retracting: sensory structures looking for guidance molecules = TELL THEM WHERE TO GROW = IN ORDER TO SYNAPSE WITH OTHER NEURONS SUCCESSFULLY (SYNAPSE) lamellipodium: flat extensions, motile structure that allows growth cone to move through its environment (MOVE)

Question 34

CAMS

Answer 34

cell adhesion molecules cue for growth cones "cellular glue": allow cone to physically grab onto the environment "stick to it" and move to its target, manufactured by other cells

Question 35

troPIC molecules

Answer 35

chemoattractants or chemorepulsants: either attract or repel pathfinding axons secreted and are diffusable

Question 36

difference between tropic and trophic

Answer 36

tropic: means movement trophic: refers to nutrition

Question 37

synaptogensis prenatally vs after birth

Answer 37

month 5: first synaptic contacts made month 7: more synaptic development of deepest cortical neurons MOST OCCURS AFTER BIRTH:

Question 38

how doies the brain/cortex mature?

Answer 38

developed/matures from bottom up

Question 39

Chisels

Answer 39

anything that facilitates synaptogenesis: genetic signals, experience, hormones, even SES

Question 40

Why does the cortex become thinner with age (usually up to 20) and what pattern does this occur in?

Answer 40

becomes thinner bc 1. synaptogensis 2. expansion of white matter presses on the cortex, "forces it" to be thinner cortical thinning occurs from back to front, just like in developmnent: caudal to rostral pattern

Question 41

at what two points does synaptic pruning peak?

Answer 41

toddlers; adolescence: why these are very drastic behavior change times

Question 42

Neural darwinism and neurotrophic factors

Answer 42

cell death occurs like natural selection: neurons must compete for neurotrophic factors (nutritional components that keep it alive) and it is survival of the fittest

Question 43

What secretes neurotrophic factors and what part of the cell receives them?

Answer 43

post-synpatic targets secrete neuotrophic factors, PRESYNPATIC recieve them

Question 44

apoptosis vs necrosis

Answer 44

apoptosis: controlled, healthy cell death/recylcing necrosis: uncontrolled, damaging cell death, explosive, unplanned

Question 45

what do radial glia become once neural migration is complete?

Answer 45

astrocytes

Question 46

oligodendrocytes

Answer 46

produce myelin in the CNS

Question 47

Myelination and maturation

Answer 47

used as an index for cerebral maturation

Question 48

myelination (stage 7) and order that structures are myelinated in

Answer 48

first occurs at 20 weeks, but majority occurs just after birth Last myelinating areas= areas that control the highest function (like the PFC) earliest myelinating: control simple movements

Question 49

sex differences in total volume, gray matter volume, white matter volume

Answer 49

total volume: males larger bc larger bodies gray matter: women peak sooner than men white matter volume: no sex differences in timing, men still have more due to body size

Question 50

What causes decrease in gray matter?

Answer 50

synaptic pruning/ apoptosis

Question 51

what increases white matter?

Answer 51

myelin development