Week 3

Question 1

3 timescales of brain plasticity

Answer 1

phylogenetic, developmental, ontogenetic (real time)

Question 2

the earliest juggling was noted around _______ __

Answer 2

1994 BC

Question 3

3 reasons for plasticity

Answer 3

changing demands through life, new skills/compensation for injury, changing environment

Question 4

brain weight at birth

Answer 4

350 g

Question 5

brain weight as adult

Answer 5

1300 g

Question 6

are all neurons born by age 2?

Answer 6

no

Question 7

neurons are added to the ____ and the _____ throughout life

Answer 7

olfactory, hippocampus

Question 8

______ cells continue to develop throughout your lifetime

Answer 8

glial

Question 9

brain volume changes from age 2 on are mainly due to _____ and _____ ______

Answer 9

myelination, dendritic branching

Question 10

neurons extend axons to connect to other neurons via ______

Answer 10

synapses

Question 11

axons must be _______ by glial cells

Answer 11

myelinated

Question 12

time range for neural progenitor proliferation

Answer 12

4-12 weeks post conception

Question 13

time range for neural migration

Answer 13

12 weeks to birth

Question 14

time range for pruning/apoptosis

Answer 14

18 weeks post conception to childhood

Question 15

time range for synaptotogenesis

Answer 15

18 weeks post conception to adolescence

Question 16

time range for myelination

Answer 16

30 weeks post conception to adulthood

Question 17

what is synaptogenesis

Answer 17

the formation of synapses

Question 18

what is synapse rearrangment

Answer 18

the loss of some synapses and development of others , to refine synaptic connections

Question 19

two kinds of regulation in brain development

Answer 19

intrinsic and extrinsic

Question 20

intrinsic regulation

Answer 20

directed by genes, activity independent. Can only go wrong without oxygen, nutrition etc, or in presence of disruptors (hormones etc. )

Question 21

extrinsic regulation

Answer 21

activity dependent - directed by neural activity, either generated spontaneously or driven by sensory input from the evironment

Question 22

about _____ as many neurons are produced as found in adult brains

Answer 22

twice

Question 23

% difference between human and chimp brain

Answer 23

1

Question 24

is the entire cortex myelinated at the same time?

Answer 24

no, different portions are myelinated at different times

Question 25

how many muscle fibers can be controlled by one neuron

Answer 25

many

Question 26

how many neurons can control one muscle fiber?

Answer 26

one

Question 27

in order to stay connected to another axon or a muscle fiber, a neuron requires ______ ______

Answer 27

trophic factors

Question 28

Hebb's rule

Answer 28

cells that fire together, wire together. Out of sync, lose your link!

Question 29

when whiskers are removed from a rat, what happens to the 'barrels' of neurons in the cortex that they map to ?

Answer 29

the adjacent barrels expand

Question 30

In Greenough's study, what were the effects of "enrichment"

Answer 30

``` heavier cerebral cortex greater cortical cell bodies more dendritic spines more branching larger synaptic contacts 20% more synapses better learning better problem solving ```

Question 31

in subordinate shrews, what was observed?

Answer 31

less branching, both apical and basal, less length in apical dendrites

Question 32

the hippocampus has an annual turnover rate of ____

Answer 32

1.75%

Question 33

adult neurogenesis is ______ in middle aged humans and mice

Answer 33

comparable