5: neurobio of normal aging 2

Question 1

fluid vs. crystallized abilities: what are they and relation to age?

Answer 1

FLUID = processing speed, problem solving, working memory, LTM, spatial ability. decline with age. CRYSTALLIZED = vocab, general knowledge, occupational expertise. don’t decline with age

Question 2

with age behavioural changes?

Answer 2

decline in cognitive and motor functions like reaction time, movement speed

Question 3

brain weight: decreases what % per ___? accompanied by?

Answer 3

2-3% per decade, after 50 years old. accompanied by an increase in ventricular volume.

Question 4

brain aging: grey vs. white matter

Answer 4

gray matter shrinks more than white matter until 50 yo, then white matter decreases more rapidly

Question 5

brain weight decreases: specific?

Answer 5

area specific: frontal cortex decreases with age while hippocampus, amygdala will have variable effectts

Question 6

neuronal death and aging?

Answer 6

thought you had more death with age, but actually little to no neuronal death in most brain regions. some areas will have loss of neurons: PFC ,cerebellum

Question 7

dendritic branching and aging in what two areas?

Answer 7

parahippocampal gyrus: dendritic branching + length is greater. PFC: decline. but pretty varialbe

Question 8

physical properties of neurons and age

Answer 8

not significantly altered: resting membrane potential, input resistance, height of AP

Question 9

LTP and age?

Answer 9

cellular basis of learning and memory, LTP harder to achieve in older animals

Question 10

mitochondrian and age?

Answer 10

young animal neurons: large number of small mitochondria. aged: small number of large mitochondria

Question 11

spine/synapse density and age?

Answer 11

regions specific variation

Question 12

ATP reserve and age?

Answer 12

aged neurons have a decreased functional reserve of ATP vs. younger neurons

Question 13

what are neurofibrillary tangles? normal?

Answer 13

cytoplasmic lesions made of hyperphosphorylated form of tau (microtubule associated protein). present in smaller number in normal aging, esp in hippocampus, entorhinal cortex, amygdala

Question 14

NFT contain? cause?

Answer 14

phophorylated neurofilaments - tau. MAP 2, other proteins. destabilize cytoskeleton = neuronal death

Question 15

neuritic plaques: what are they and contain?

Answer 15

spherical multicellular lesions. AB peptides, surrounded by dystrophic neurites, activated microglia, reactive astrocytes

Question 16

how are AB peptides deposited?

Answer 16

diffuse plaques, then primitive plaques, then senile plaques, then burned out plaques.

Question 17

normal aging: AB deposits?

Answer 17

see large number of diffuse deposits. (vs .AD which is more senile plaques)