Transcript ppt
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