Aging Week 3 Summary 3 (PDF)

3.1 aging changes in the neurological system degeneration of the CNS neurodegenerative conditions and aging ex: - PD -ALS - HD - risk factor: increasing age primary hallmarks of aging driving neurodegeneration - genomic instability: - DNA damage over time - incr...

3.1 aging changes in the neurological system degeneration of the CNS neurodegenerative conditions and aging ex: - PD -ALS - HD - risk factor: increasing age primary hallmarks of aging driving neurodegeneration - genomic instability: - DNA damage over time - increased need for DNA repair - decreased levels of NAD+ and sirtuins telomere attrition - shortening of telomeres w age - impact on cellular aging epigenetic alterations - changes in gene expression regulation loss of proteostasis - decline in protein quality control - accumulation of misfolded proteins mechanisms and effects DNA damage and repair - ongoing DNA damage leads to cellular synthesis - increased overall inflammation mitochondrial dysfxn - contributes to decreased central nervous system function inflammation - accelerates the aging process - interaction of genomic instability, telomere attrition, epigenetic changes, and proteostasis loss leads to neurodegeneration - aging as a significant risk factor for neurological diseases thru these mechanisms changes in brain structure ventral dilation and neuron changes ventral Dilation - some degree is expected w aging cortical neurons - shrinkage occurs - # remains relatively the same cortical atrophy affected areas: - frontal cortex - temporal cortex - prefrontal cortex - potentially the hippocampus (memory capacity) minimal atrophy: - subcortical nuclei, except possibly the substantia nigra - impact on dopamine use by the strata brain wt and size - atrophy effect: - decrease in brain wt w age variability: - normal variability in brain sizes among individuals  normal aging involves specific patterns of atrophy and neuron shrinkage significant areas include the frontal and temporal cortices, and potentially the hippocampus, w minimal impact on subcortical nuclei except the substantia nigra physiologic changes to vasculature in the CNS arterial wall changes loss of elasticity: - increased likelihood of atherosclerosis (not considered normal aging) tortuosity: - vessels become more tortuous or windy - slower perfusion of brain tissue BBB Changes - decreased protectiveness: - decreased waste elimination - impaired reactivity in brain vasculature to meet demands neural processing efficiency reduced efficiency: - decreased myelin - decreased vasodilation capacity changes in the brain's vascular system contribute to reduced neural processing efficiency includes loss of arterial elasticity, increased vessel tortuosity, decreased blood-brain barrier protectiveness, and impaired waste elimination and vasculature reactivity impact on cognition seattle longitudinal study findings overall cognition: - linear age-related declines observed areas of rapid decline: - processing speed - episodic memory - spatial ability - reasoning minimal change: - numeric ability - verbal ability cognitive decline and mortality related studies: - plotted mortality based on cognitive decline acceleration of cognitive decline: - begins approximately 3-6 years before death significant cognitive declines in certain areas w aging acceleration of cognitive decline near end of life impact of cognition fxn memory and processing speed short term memory: - modest decline processing speed: - continued decline throughout adulthood verbal intelligence and personality verbal intelligence: - stable until the 60s personality: - no substantial changes sleep patterns variability: - more variable sleep patterns and duration frequent awakenings and naps: - increased frequency challenges w normal aging info processing: - decreased fluidity and speed impacting intelligence attention: - decreased stability to divide attention executive tasks: - challenges w new tasks learning and recall: - decreased learning and recall of new info word finding: - challenges w spontaneous word finding mental flexibility and reaction time: - decreased mental flexibility - increased reaction time maintained fxns independence w general fxns: - attention span - real world executive fxn - comprehension and vocabulary - long-term procedural memory aging involves specific cognitive and functional changes while maintaining certain abilities and independence in general fxns reversible changes focus: evidence supporting reversibility of cognitive decline with physical activity and nutrition accelerated changes and cognitive impairment - early onset: - accelerated changes leading to mild cognitive impairment (MCI) or dementia impact of physical activity - mitigation and reversal: - role of physical activity in reducing and possibly reversing biological hallmarks of aging role of nutrition - mitigating effects: - contribution of nutrition to combating aging-related cognitive decline future directions - research trends - further investigation into mechanisms of reversibility - integration of physical activity and nutrition in cognitive health strategies both physical activity and nutrition demonstrate potential to mitigate and reverse buildup of aging biological hallmarks associated with cognitive decline continued research is crucial to fully understand and optimize these interventions in the peripheral nervous system brain fxn processing and reaction time: - decreased w age - impact on overall cognitive fxn peripheral nervous system - impact on sgnaling feedback: - quality and quantity affected by decreased fxn structural changes in the PNS myelin sheath health: - decreased due to impaired remyelination by oligodendrocytes nerve conduction velocity: - slowed due to reduced myelin integrity other impacts on PNS endoneurial blood flow: - decreased nerve regeneration and repair capacity: - impaired - protein transport: - affected microglia and astrocytes fxn: - impaired fxn neuromuscular jxn changes structural alterations: - impact on nerve signaling aging affects both central and PNS fxn decreased processing and reaction time influences somatosensory, visual, and vestibular signaling structural changes in the PNS contribute to reduced nerve conduction velocity, impaired regeneration, and altered neuromuscular junction signaling impact on PNS fxn vision depth perception and visual acuity: - difficulty due to decreased lens elasticity - impacts on accurate depth perception hearing - upward gaze and high-frequency sounds: - limitation of upward gaze - loss of acuity for high-frequency sounds somatosensory and spinal reflexes general changes: - altered processing in somatosensory perception - changes in spinal reflex responses gait and posture age-related changes: - normal alterations in gait and posture - not typically leading to false perceptions or balance issues aging affects sensorineural processes across vision, hearing, somatosensory perception, spinal reflexes, gait, and posture important to note changes in depth perception, visual acuity, upward gaze, high-frequency sound perception, and normal gait and posture alterations impact on vision cataracts - blurry vision due to protein buildup on the lens - no change in field of vision impact: - overall vision becomes progressively blurry glaucoma - optic nerve damage caused by elevated intraocular pressure - leads to tunnel vision impact: - gradual loss of peripheral vision macular degeneration - degeneration of the macula, central part of the retina - decreased central vision impact - increased reliance on peripheral vision -cataracts: blurry vision without peripheral vision loss -glaucoma: tunnel vision due to peripheral field loss -macular degeneration: central vision loss, increased dependence on peripheral vision these conditions represent abnormal changes in vision with age, necessitating medical attention Summary Known changes in nervous system function and structure occur with age, but are reversible this bish..stays doing the most. this shouldnt be 5 pages  3.2 impact of exercise on aging neurological system physiological impact in the CNS intro to exercise and metabolic switching - exercise induces intermittent metabolic switching - body's response to demands leads to metabolic rate changes effects on ketones and synaptic activity - increased buildup of ketones - enhanced synaptic activity impact on trophic factors - brain derived neurotrophic factor (BDNF) - fibroblast growth factor 2 (FGF-2) - vascular endothelial growth factor (VEGF) activation of signaling pathways - concurrent activation of pathways - Induction of transcription factors enhancement of neuroplasticity and resilience - genes encoding proteins for neuroplasticity - resilience during aging overall effect on physiological aging - minimization of maladaptations - promotion of healthy aging processes impact on cerebral blood flow impact of exercise on brain - increased cerebral blood flow and basal reactivity - decreased brain atrophy over time cognitive fxn improvement - neuroprotection effects - increased cerebral vascular and cognitive reserve specific effects on aging - normal aging effects on blood flow. - decreased flow in frontal and parietal lobes. - increased flow in cingulate and insular regions - contrasting effects in pathologies like mild cognitive impairment or dementia comparison of active vs. sedentary lifestyles - differences in blood flow patterns study ex - impact of 12 wks of aerobic exercise - reversal of blood flow discrepancy towards left insula - improved working memory and verbal fluency demonstrated by participants neuroprotective effects neuroprotective effects of exercise on endothelial fxn - exercise enhances endothelial function in the central nervous system - increased production of growth factors: - peripherally produced growth factors entering systemic circulation - brain-produced factors improvements in neurotransmitter modulation - enhanced synaptic function and plasticity - improved energy metabolism - promotion of neurogenesis and cell survival additional impact on cognitive focus on executive function, memory, and neuroplasticity - emphasis on brain's executive fxn and memory - + effects of exercise on neuroplasticity additional effects of physical activity - cascade of effects on hormone levels: - serotonin. - melatonin. - dopamine. - impact on mood regulation. - decrease in depressive sx’s demonstrated in multiple studies. impact on brain structure impact on brain structure study by erikson et al. (2010) - randomized controlled study. - participants: 120 pts w/o dementia. - intervention groups: - aerobic exercise 3x a wk at mod intensities - stretching group results: - aerobic group: 1.97 to 2.12% increase in hippocampal volume - stretching group: 1.4% loss in hippocampal volume conclusion: aerobic exercise can reverse 1 to 2% annual hippocampal volume loss attributed to age in healthy adults supporting studies - other studies on progressive resistance training - similar positive results observed overall benefit - promotion of both exercise interventions shown to be beneficial impact at the neuromuscular jxn impact on the peripheral nervous system - focus on the neuromuscular junction. - changes during normal aging: - more mitochondria, deeper postsynaptic junctions, densely located acetylcholine receptors. - aging effects: fewer mitochondria, shallower junctions, fewer activated receptors. effects of physical activity - induces: - increased mitochondrial genesis. - improved mitochondrial function and ATP availability. - increased pre- and post-synaptic activity. - increased # of receptors. summary