6C. Adult and Aging Brain

Question 1

Changes in grey and white matter between childhood and adulthood

Answer 1

Grey matter decreases as excess neurons are pruned. White matter increases as connections between separate brain areas are strengthened

Question 2

When does the rate of pruning begin to slow down?

Answer 2

Late 20s

Question 3

When does white matter volume peak?

Answer 3

Age 40

Question 4

How are brain networks organized during childhood and adolescence?

Answer 4

More locally organized

Question 5

When does intelligence peak?

Answer 5

Ages 25 to 60

Question 6

Fluid intelligence

Answer 6

Problem solving and pattern identification. Peaks around 30

Question 7

Crystallized intelligence

Answer 7

Vocabulary and knowledge of facts. Increases until 50

Question 8

There is no single age at which all cognitive functions are at their peak. True or false?

Answer 8

True

Question 9

Widespread and profound loss of neurons is part of normal aging. True or false?

Answer 9

False

Question 10

When does cognition start declining?

Answer 10

Some say 20s to 30s, some say 50s to 60s

Question 11

Most common cognitive change

Answer 11

Memory decline

Question 12

How are the different types of memory and attention affected?

Answer 12

Declarative memory declines, nondeclarative memory remains intact, working memory declines starting at 30. Selective attention and divided attention decline

Question 13

When does brain volume begin to decline?

Answer 13

Around 30s to 40s, starts declining at a greater rate around 60

Question 14

Brain regions that exhibit the greatest loss in volume

Answer 14

PFC, cerebellum, hippocampus

Question 15

Changes at cellular level that contribute to decrease in volume

Answer 15

Shrinking neurons, retraction and decreased complexity of dendrites, loss of myelin

Question 16

Regions where thinning of cerebral cortex is most pronounced

Answer 16

Frontal lobes and parts of temporal lobes

Question 17

Last in, first out theory

Answer 17

Last parts of brain to develop are the first to deteriorate. Temporal and frontal lobes show greatest declines in volume and cortical thickness, and are also the areas that take the longest to reach maturity. Fibres that are the last to mature also deteriorate first.

Question 18

Synaptic changes have a greater effect than structural and chemical changes. True or false?

Answer 18

True

Question 19

Study in rhesus monkeys observed that the aging process targets…

Answer 19

Thin spines. Small and slender, highly plastic, extend and retract faster than larger “mushroom” spines. Led to speculation that thin spines are involved in working memory, which requires a high degree of plasticity.

Question 20

Two regions that continue to add new neurons throughout life

Answer 20

Olfactory bulbs and dentate gyrus of hippocampus

Question 21

Two neurotransmitters decline with age

Answer 21

Dopamine and serotonin

Question 22

Genes that are expressed less in older brains

Answer 22

Genes important for plasticity

Question 23

Describe effect of oxidative stress on DNA

Answer 23

Mitochondria produce free radicals as byproducts, will destroy fats, proteins, and DNA if left unchecked. Defense mechanisms against free radicals decline with age. Damage to mDNA in brain cells accumulates.

Question 24

2 factors that make the brain more vulnerable to changes

Answer 24

Large energy requirements (20% of body’s fuel). Neurons aren’t replaced as often as other cells.

Question 25

Immune dysfunction

Answer 25

Microglia become more reactive.

Question 26

Diets linked to better brain health

Answer 26

Mediterranean, DASH (dietary approaches to stop hypertension)

Question 27

Nutrients linked to better brain health

Answer 27

Antioxidants (vitamins C and E), flavonoids, omega-3

Question 28

Exercise is linked to…

Answer 28

Reduced cortical thinning and less shrinkage in hippocampus. Improves neuroplasticity and neurogenesis. Improves blood flow and increases production of neurotrophic factors.