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Biological Myths of Aging
•Memory declines drastically with age for all people.
•IQ declines drastically with age in all people.
•Learning becomes more difficult as we get older.
•There is nothing you can do counter these aging deficits.
Physical Decline with Aging
Nervous
System
Decline with
Age
•Decrease in brain size/weight
•steady, slow, and mild
•Decrease in Brain blood flow
•Decrease in the use of Glucose
•Decrease in Sensory Systems
Brain Weight and Aging
Senses Decline with Aging
Memory Decline with Aging
Age-Related Deficits:
•long-term memory
•physical-motor tasks
•free recall learning
•requiring conscious recollection and effort
No Age-Related Deficits:
•short-term memory
•non physical-motor tasks
•recognition learning
•easily organized task structures or cues
Recall and
Recognition
in Adulthood
•Recognition
•stable
•Recall
•declines
Intelligence and Aging
Reducing Cognitive Decline
1. Live in Favorable Environmental Circumstances
above-average education
high complexity occupations
above-average income
maintaining intact families
2. Be involved in activities typical of complex and intellectually
stimulating environments
extensive reading
travel
attending cultural events
continuing education activities
participation in clubs and professional associations
3. Be married to a spouse with high cognitive status
Conclusion
•Only certain types of memory show declines with aging.
•IQ does not show a drastic decline with age.
•The ability to learn does not deviate much as we get older.
•There is plenty you can do counter aging deficits.
•Stop smoking
•Exercise regularly
•Eat properly
•Engage in learning activities
•Stay in touch with friends, families, communities
Dementia
•Cognitive disorder that involves a gradual
deterioration of brain functioning that affects
judgement, memory, language, and other
cognitive processes
• Caused my several different medical
conditions (Alzheimer's, Parkinson's,
Huntington’s, syphilis, stroke, HIV, head
trauma) and by abuse of alcohol and drugs
Alzheimer's Disease: Symptoms
• memory impairment
–starts slow and gradual
–forget events, lose objects
• agnosia - can’t recognize objects
• aphasia - language problems
• apraxia - motor problems
• emotional changes
–aggressive, agitated, public displays, wandering
• average survival is 8-10 years
Alzheimer's
Prevalence
by Age
Alzheimer's: Biology
• chromosomes 1, 14, 19, and 21
• general brain atrophy
• neuronal degeneration
• decreased cerebral metabolism
• general decay of acetylcholine system
– especially in the basal forebrain
• neurofibrillary tangles
• beta-amyloid plaques
General Brain Atrophy
Neuronal Degeneration
Normal
Alzheimer’s
Decreased Cerebral Metabolism
Alzheimer's
Normal
Decay of Acetylcholine System
*
Neurofibrillary
Tangles
Microtubules:
•Provide structural support
•Are pathways for:
•Nutrients
•Waste products
•Neurotransmitters
Made of Tubulin
In Alzheimer’s Disease:
Excess Tau protein binds builds up
Tau binds with Tubulin and tangles the
microtubules preventing them from
properly functioning
Beta-Amyloid Plaque Formation
Key enzymes:
•Alpha-secretase
•Beta-secretase
•Gamma-secretase
Protein fragments:
p3
alpha and gamma
harmless
40 amino acid string
beta and gamma
harmless
42 amino acid string
beta and gamma
TOXIC
Beta-Amyloid Precursor Protein (BAPP)
is cut or cleaved by these enzymes
three different protein fragments form
Beta-Amyloid Plaques
Beta-Amyloid Plaques
Tau Filaments
Pathology:
•Interferes with Ca2+ regulation
•Increases free radicals
•Stimulates mircroglia aggregation
•Increases inflammation
Alzheimer's: Treatment
• nothing can correct the damage
• possible agents that slow the deterioration:
– education
– tacrine hydrochloride
– estrogen replacement therapy
– vitamin E
– aspirin
• helping patients adjust to memory loss
– memory wallet, key baskets, tags
Alzheimer's: Memory Tricks
Alzheimer's Cure?
• Vaccine?
– using the beta-amyloid peptide fragments
• Gamma-Secretase Inhibitors?
– to block the inappropriate cleavage of the
beta-amyloid precursor protein