Development of Brain Continued

Question 1

continues throughout adulthood, guided by experience

Answer 1

synapse rearrangement

Question 2

typically weaker or inactive synapses are pruned away and the stronger ones remain, this allows for:

Answer 2

more efficient neural communication and signaling

Question 3

the cortical thinning process continues from caudal to rostral throughout maturation reaching the … last, which may contribute to teenagers impulsivity

Answer 3

prefrontal cortex

Question 4

is the most frequent inherited cause of intellectual disability, which ranges from mild to severe

Answer 4

Fragile X

Question 5

in humans and mice with this disorder, cortical neurons have excessive immature … so normal elimination of synapses doesn’t occur

Answer 5

dendritic spines

(the extra inefficient synapses interfere with cognition and behavior)

Question 6

impairment of vision in one eye with inability to see clear forms; lazy eye

• if h=this eye isn’t strengthened, the brain will ignore the image coming in from the weaker eye

Answer 6

amblyopia

Question 7

is when one eye is misaligned, which results in double-vision

Answer 7

strabismus

Question 8

if not realigned in childhood, the individual will not have good visual acuity (or accuracy) or

Answer 8

depth perception

Question 9

preventing sight in both eyes, results in a loss of dendritic spines and a reduction in synapses in the visual cortex

Answer 9

binocular deprivation

• if deprivation lasts long enough, sight can never be restored

Question 10

the … of development is when experience or treatment can make permanent alterations

Answer 10

sensitive period

Question 11

during this period causes significant reorganization throughout the brain (from the eye to the thalamus and cortex) and permanently impairs vision in the deprived eye

Answer 11

monocular deprivation

• normally most neurons in the visual cortex respond equally to light presented to either eye, with md, most cortical neurons respond only to input from the non-deprived eye

Question 12

grow stronger or weaker depending on their ability to affect a postsynaptic cell

Answer 12

hebbian synapses

• cells that fire together, wire together

Question 13

together these findings demonstrate…

Answer 13

importance of early experience in organizing the visual system

Question 14

the sum of an individuals intrinsic, genetic information; constant (that is, your genes)

Answer 14

genotype

Question 15

the sum of an individual’s physical characteristics; changes constantly based on extrinsic effects on genes, including environment, experience, etc.

Answer 15

phenotype

Question 16

genes are intrinsic factors that develop WITHIN the cell – all other influences are extrinsic

Question 17

differences in experiences produce different phenotypes and behaviors

Answer 17

identical twins

Question 18

an example of the effect of genetics combined with experience can be seen in individuals with …

Answer 18

phenylketonuria (PKU)

Question 19

PKU causes inability of the individual to … an amino acid present in many foods

Answer 19

metabolize phenylalanine

Question 20

is the study of the factors that change gene expression without changing the gene sequences

Answer 20

epigenetics

Question 21

• genes code for proteins
• changing gene expression changes the amount of protein that is produced
• proteins code for things like hormone receptors: the level of hormone receptors can significantly change behavior

Answer 21

why does changing gene expression matter?

Question 22

experiences and environment can add or remove things to the DNA (without changing the DNA sequence itself) to make it more or less capable of being transcribed and producing proteins

Answer 22

how can you change gene expression?

Question 23

one example is … where a methyl group (CH3) is added on to the DNA and reduces gene expression

Answer 23

methylation

Question 24

neither! it depends on the environment in which they live

Answer 24

which phenotype is better? one that is more anxious or less anxious?