Disruption of large-scale brain systems in advanced aging
Jessica R Andrews-Hanna1, Abraham Z Snyder, Justin L Vincent
1Department of Psychology, Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.
Neuron
|December 7, 2007
Summary
Normal aging disrupts brain system coordination, leading to cognitive decline. This study shows reduced functional connections in older adults, independent of Alzheimer's disease (AD), linked to white matter integrity and cognitive performance.
Area of Science:
- Neuroscience
- Cognitive Aging Research
- Brain Systems Coordination
Background:
- Cognitive decline is common in normal aging, even without disease.
- Alterations in large-scale brain system coordination may underlie age-related cognitive changes.
Purpose of the Study:
- To investigate if normal aging involves disruptive alterations in brain system coordination.
- To identify specific brain networks affected by aging and their relation to cognitive function.
Main Methods:
- Studied 93 adults aged 18-93 using functional correlation analysis.
- Assessed Alzheimer's disease (AD) pathology via amyloid imaging.
- Examined white matter integrity and cognitive performance across various domains.
Main Results:
- Aging significantly reduced functional correlations within two higher-order brain systems.
- Default network's anterior-posterior components showed the most severe age-related disruption.
- Reduced correlations persisted in individuals without AD pathology and were linked to impaired white matter integrity and cognitive function.
Conclusions:
- Cognitive decline in normal aging stems from disrupted coordination of large-scale brain systems.
- Functional disruptions in brain networks are a key feature of aging, not solely attributable to AD.
- White matter integrity is crucial for maintaining cognitive function during aging.
Related Concept Videos
01:26Aging
Aging is a complex biological phenomenon influenced by various processes that affect cellular and systemic functions. Several prominent theories attempt to explain its mechanisms, highlighting cellular limitations, oxidative damage, and hormonal changes as central factors in aging.
Cellular Clock Theory
The cellular clock theory posits that the human lifespan is closely tied to the finite capacity of cells to divide, a phenomenon governed by telomeres, which are protective caps at the ends of...
Cellular Clock Theory
The cellular clock theory posits that the human lifespan is closely tied to the finite capacity of cells to divide, a phenomenon governed by telomeres, which are protective caps at the ends of...
01:23Alzheimer Disease ll: Pathophysiology
Alzheimer disease involves structural changes in the brain that begin long before symptoms appear. The most distinctive features are extracellular neuritic plaques and intracellular neurofibrillary tangles.Neuritic plaques form in the cerebral cortex and around blood vessels. These plaques contain a dense core of beta-amyloid (Aβ)—a toxic protein fragment that clumps outside neurons. The core is surrounded by damaged neuronal extensions, as well as reactive astrocytes and microglia. Abnormal...
01:22Dementia l: Introduction
Dementia is an acquired, progressive syndrome characterized by a decline in multiple cognitive domains severe enough to impair daily functioning and reduce independence. Although memory loss is a central feature, the diagnosis requires additional deficits involving language, executive function, visuospatial skills, judgment, calculation, or abstract reasoning. These cognitive impairments reflect underlying neurodegenerative or vascular processes that gradually disrupt neuronal networks...
01:29Alzheimer Disease l: Introduction
Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated...
01:30Cognitive Development During Adulthood
Cognitive development continues throughout adulthood, undergoing significant shifts across early, middle, and late stages. Individual transition occurs from adolescent idealism to pragmatic and adaptable thinking in early adulthood. During this period, individuals learn to integrate personal beliefs with the recognition that other perspectives are equally valid. Exposure to the complexities of modern society, diverse experiences, and higher education contribute to this adaptive thought process,...
01:28Disorders of the Nervous Tissue
Nervous tissue is a vital component of the human body's communication system, enabling us to perceive and respond to stimuli. However, like all other tissues, it is vulnerable to disorders and diseases that can significantly impact our neurological functioning.
Homeostatic Imbalances:
Alzheimer's disease manifests as a gradual decline in memory and cognitive abilities, attributed to the buildup of amyloid plaques and neurofibrillary tangles in the brain.
Parkinson's disease arises from the...
Homeostatic Imbalances:
Alzheimer's disease manifests as a gradual decline in memory and cognitive abilities, attributed to the buildup of amyloid plaques and neurofibrillary tangles in the brain.
Parkinson's disease arises from the...