scholarly journals Differential patterns of gyral and sulcal morphological changes during normal aging process

2020 ◽  
Author(s):  
Hsin-Yu Lin ◽  
Chu-Chung Huang ◽  
Kun-Hsien Chou ◽  
Albert C. Yang ◽  
Chun-Yi Zac Lo ◽  
...  
Keyword(s):  
White Matter ◽  
Aging Process ◽  
Morphological Changes ◽  
Normal Aging ◽  
Quadratic Model ◽  
Imaging Data ◽  
Cortical Folding ◽  
Brain Functioning ◽  
Age Related ◽  
Morphological Model

ABSTRACTThe cerebral cortex is a highly convoluted structure with distinct morphologic features, namely the gyri and sulci, which are associated with the functional segregation or integration in the human brain. During the lifespan, the brain atrophy that is accompanied by cognitive decline is a well-accepted aging phenotype. However, the detailed patterns of cortical folding change during aging, especially the changing trajectories of gyri and sulci, which is essential to brain functioning, remain unclear. In this study, we investigated the morphology of the gyral and sulcal regions from pial and white matter surfaces using MR imaging data of 417 healthy participants across the lifespan (21-92y). To elucidate the age-related changes in the cortical pattern, we fitted cortical thickness and intrinsic curvature of gyri and sulci using the quadratic model to evaluate their trajectories during normal aging. Our findings show that comparing to gyri, the sulcal thinning is the most prominent pattern during the aging process, and the gyrification of pial and white matter surfaces were also affected differently, which implies the vulnerability of functional segregation during aging. Taken together, we propose a morphological model of aging that may provide a framework for understanding the mechanisms underlying the gray matter degeneration.

scholarly journals Differential Patterns of Gyral and Sulcal Morphological Changes During Normal Aging Process

2021 ◽  
Vol 13 ◽  
Author(s):  
Hsin-Yu Lin ◽  
Chu-Chung Huang ◽  
Kun-Hsien Chou ◽  
Albert C. Yang ◽  
Chun-Yi Zac Lo ◽  
...  
Keyword(s):  
White Matter ◽  
Aging Process ◽  
Morphological Changes ◽  
Normal Aging ◽  
Quadratic Model ◽  
Imaging Data ◽  
Cortical Folding ◽  
Brain Functioning ◽  
Age Related ◽  
Morphological Model

The cerebral cortex is a highly convoluted structure with distinct morphologic features, namely the gyri and sulci, which are associated with the functional segregation or integration in the human brain. During the lifespan, the brain atrophy that is accompanied by cognitive decline is a well-accepted aging phenotype. However, the detailed patterns of cortical folding change during aging, especially the changing age-dependencies of gyri and sulci, which is essential to brain functioning, remain unclear. In this study, we investigated the morphology of the gyral and sulcal regions from pial and white matter surfaces using MR imaging data of 417 healthy participants across adulthood to old age (21–92 years). To elucidate the age-related changes in the cortical pattern, we fitted cortical thickness and intrinsic curvature of gyri and sulci using the quadratic model to evaluate their age-dependencies during normal aging. Our findings show that comparing to gyri, the sulcal thinning is the most prominent pattern during the aging process, and the gyrification of pial and white matter surfaces were also affected differently, which implies the vulnerability of functional segregation during aging. Taken together, we propose a morphological model of aging that may provide a framework for understanding the mechanisms underlying gray matter degeneration.

scholarly journals Physiological and Pathological Ageing of Astrocytes in the Human Brain

2021 ◽  
Author(s):  
Marloes Verkerke ◽  
Elly M. Hol ◽  
Jinte Middeldorp
Keyword(s):  
Risk Factor ◽  
Morphological Changes ◽  
Ion Homeostasis ◽  
Brain Functioning ◽  
Physiological Ageing ◽  
Human Astrocytes ◽  
Age Related ◽  
Technical Issues ◽  
Neuronal Transmission ◽  
Ageing Brain

AbstractAgeing is the greatest risk factor for dementia, although physiological ageing by itself does not lead to cognitive decline. In addition to ageing, APOE ε4 is genetically the strongest risk factor for Alzheimer’s disease and is highly expressed in astrocytes. There are indications that human astrocytes change with age and upon expression of APOE4. As these glial cells maintain water and ion homeostasis in the brain and regulate neuronal transmission, it is likely that age- and APOE4-related changes in astrocytes have a major impact on brain functioning and play a role in age-related diseases. In this review, we will discuss the molecular and morphological changes of human astrocytes in ageing and the contribution of APOE4. We conclude this review with a discussion on technical issues, innovations, and future perspectives on how to gain more knowledge on astrocytes in the human ageing brain.

scholarly journals White Matter Microstructure Predicts Focal and Broad Functional Brain Dedifferentiation in Normal Aging

2020 ◽  
Vol 32 (8) ◽  
pp. 1536-1549
Author(s):  
Jenny R. Rieck ◽  
Karen M. Rodrigue ◽  
Denise C. Park ◽  
Kristen M. Kennedy
Keyword(s):  
Visual Cortex ◽  
White Matter ◽  
Visual Processing ◽  
Brain Activity ◽  
Normal Aging ◽  
Important Variable ◽  
Functional Selectivity ◽  
Functional Responses ◽  
Age Related ◽  
Function Relationship

Ventral visual cortex exhibits highly organized and selective patterns of functional activity associated with visual processing. However, this specialization decreases in normal aging, with functional responses to different visual stimuli becoming more similar with age, a phenomenon termed “dedifferentiation.” The current study tested the hypothesis that age-related degradation of the inferior longitudinal fasciculus (ILF), a white matter pathway involved in visual perception, could account for dedifferentiation of both localized and distributed brain activity in ventral visual cortex. Participants included 281 adults, ages 20–89 years, from the Dallas Lifespan Brain Study who underwent diffusion-weighted imaging to measure white matter diffusivity, as well as fMRI to measure functional selectivity to viewing photographs from different categories (e.g., faces, houses). In general, decreased ILF anisotropy significantly predicted both focal and broad functional dedifferentiation. Specifically, there was a localized effect of structure on function, such that decreased anisotropy in a smaller mid-fusiform region of ILF predicted less selective (i.e., more dedifferentiated) response to viewing faces in a proximal face-responsive region of fusiform. On the other hand, the whole ILF predicted less selective response across broader ventral visual cortex for viewing animate (e.g., human faces, animals) versus inanimate (e.g., houses, chairs) images. This structure–function relationship became weaker with age and was no longer significant after the age of 70 years. These findings indicate that decreased white matter anisotropy is associated with maladaptive differences in proximal brain function and is an important variable to consider when interpreting age differences in functional selectivity.

Effects of Aging on Impairment Ratings: Part 2: Internal Medicine Issues

2018 ◽  
Vol 23 (6) ◽  
pp. 9-13
Author(s):  
Stephen L. Demeter
Keyword(s):  
Internal Medicine ◽  
Aging Process ◽  
Digestive System ◽  
The United States ◽  
Normal Aging ◽  
Infectious Hepatitis ◽  
Female Reproductive Tract ◽  
Ulcer Disease ◽  
Age Related ◽  
Impairment Ratings

Abstract This is the second of four articles that explore the effects of age-related changed in impairment evaluations according to the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides), Fifth and Sixth Editions; specifically, this article completes the review of the internal medicine sections. With respect to the digestive system, the normal aging process affects gastrointestinal impairment ratings as found in the AMA Guides, Fifth and Sixth Editions, for gastroesophageal reflux disease, peptic ulcer disease, pancreatitis, diverticulitis, irritable bowel syndrome, fecal incontinence, and hemorrhoids. Cancers of the digestive system and infectious hepatitis were reviewed by the National Institutes of Health in The Burden of Digestive Diseases in the United States (2008), which should be reviewed when an impairment rating or apportionment is needed or for an individual with these conditions alleged to be the result of a compensable injury or illness. The normal aging process does not significantly affect the impairment ratings for renal disease (upper urinary tract disease), but, for individuals over 70, an age adjustment should be incorporated into the impairment rating. The AMA Guides, Fifth and Sixth Editions, also do not provide age-related modifications for urinary incontinence, but a rating physician may apply a discretionary apportionment. For diseases of the scrotum, testicles, epididymis, and spermatic cord, as well as for prostatic hypertrophy, neither edition of the AMA Guides makes age-related modifications; neither are modifications because of aging are made for the female reproductive tract, although raters are told to consider the physiological differences.

scholarly journals T Cells Actively Infiltrate the White Matter of the Aging Monkey Brain in Relation to Increased Microglial Reactivity and Cognitive Decline

2021 ◽  
Vol 12 ◽  
Author(s):  
Katelyn V. Batterman ◽  
Payton E. Cabrera ◽  
Tara L. Moore ◽  
Douglas L. Rosene
Keyword(s):  
T Cells ◽  
T Cell ◽  
White Matter ◽  
Cognitive Decline ◽  
Normal Aging ◽  
Cell Infiltration ◽  
Cingulum Bundle ◽  
T Cell Infiltration ◽  
Age Related ◽  
Related Increase

Normal aging is characterized by declines in processing speed, learning, memory, and executive function even in the absence of neurodegenerative diseases such as Alzheimer's Disease (AD). In normal aging monkeys and humans, neuronal loss does not account for cognitive impairment. Instead, loss of white matter volume and an accumulation of myelin sheath pathology begins in middle age and is associated with cognitive decline. It is unknown what causes this myelin pathology, but it likely involves increased neuroinflammation in white matter and failures in oligodendrocyte function (maturation and repair). In frontal white matter tracts vulnerable to myelin damage, microglia become chronically reactive and secrete harmful pro-inflammatory cytokines. Despite being in a phagocytic state, these microglia are ineffective at phagocytosing accruing myelin debris, which directly inhibits myelin sheath repair. Here, we asked whether reported age-related increases in pro-inflammatory markers were accompanied by an adaptive immune response involving T cells. We quantified T cells with immunohistochemistry in the brains of 34 cognitively characterized monkeys and found an age-related increase in perivascular T cells that surround CNS vasculature. We found a surprising age-related increase in T cells that infiltrate the white matter parenchyma. In the cingulum bundle the percentage of these parenchymal T cells increased with age relative to those in the perivascular space. In contrast, infiltrating T cells were rarely found in surrounding gray matter regions. We assessed whether T cell infiltration correlated with fibrinogen extravasation from the vasculature as a measure of BBB leakiness and found no correlation, suggesting that T cell infiltration is not a result of passive extravasation. Importantly, the density of T cells in the cingulum bundle correlated with microglial reactivity and with cognitive impairment. This is the first demonstration that T cell infiltration of white matter is associated with cognitive decline in the normal aging monkey.

scholarly journals White matter microstructure predicts focal and broad functional brain dedifferentiation in normal aging

2019 ◽  
Author(s):  
Jenny R. Rieck ◽  
Karen M. Rodrigue ◽  
Denise C. Park ◽  
Kristen M. Kennedy
Keyword(s):  
Visual Cortex ◽  
White Matter ◽  
Visual Processing ◽  
Brain Activity ◽  
Normal Aging ◽  
Important Variable ◽  
Functional Selectivity ◽  
Functional Responses ◽  
Age Related ◽  
Function Relationship

AbstractVentral visual cortex exhibits highly organized and selective patterns of functional activity associated with visual processing. However, this specialization decreases in normal aging, with functional responses to different visual stimuli becoming more similar with age, a phenomenon termed “dedifferentiation”. The current study tested the hypothesis that age-related degradation of the inferior longitudinal fasciculus (ILF), a white matter pathway involved in visual perception, could account for dedifferentiation of both localized and distributed brain activity in ventral visual cortex. Participants included 281 adults, ages 20-89, from the Dallas Lifespan Brain Study who underwent diffusion-weighted imaging to measure white matter diffusivity, as well as functional magnetic resonance imaging to measure functional selectivity to viewing photographs from different categories (e.g., faces, houses). In general, decreased ILF anisotropy significantly predicted both focal and broad functional dedifferentiation. Specifically, there was a localized effect of structure on function, such that decreased anisotropy in a smaller mid-fusiform region of ILF predicted less selective (i.e., more dedifferentiated) response to viewing faces in a proximal face-responsive region of fusiform. On the other hand, the whole ILF predicted less selective response across broader ventral visual cortex for viewing animate (e.g., human faces, animals) versus inanimate (e.g., houses, chairs) images. This structure-function relationship became weaker with age and was no longer significant after age 70. These findings indicate that decreased white matter anisotropy is associated with maladaptive differences in proximal brain function and is an important variable to consider when interpreting age differences in functional selectivity.

scholarly journals Brain volumetric MRI study in healthy adolescent and young person’s using automated method

2021 ◽  
Vol 8 (9) ◽  
pp. 531-537
Author(s):  
Seda Avnioğlu ◽  
Özkan Özen
Keyword(s):  
Magnetic Resonance Imaging ◽  
White Matter ◽  
Magnetic Resonance ◽  
Morphological Changes ◽  
Young Subject ◽  
Resonance Imaging ◽  
Brain Volumes ◽  
Healthy Adolescent ◽  
Automated Method ◽  
Age Related

Objective: Adolescence is a critical period for the maturation of neurobiological processes that underlie higher cognitive functions and social and emotional behaviour. However, there are limited studies that investigated brain volumes in healthy adolescents and young persons.  The aim of this study was to compare the Grey Matter (GM), White Matter (WM) and some specific brain subcortical volumes such as hippocampus and amygdala between healthy adolescents and young groups by using VolBrain. Material and Methods: Magnetic resonance imaging brain scans were retrospectively obtained from 20 healthy adolescent and young subjects.  The mean ages of the adolescent and young persons were 13±1 and 24±2, respectively. Brain parenchyma (BP), GM, WM and asymmetry features were calculated using VolBrain, and the GM and WM volumes of each subjects were compared with those of the both groups. The current study to examine whether regional gray matter (GM), white matter (WM), cerebrospinal fluid (CSF), some brain subcortical structures volumes differed between healthy adolescent and young groups. Also, of the whole brain, hemispheres, and hippocampus, amigdala of adolescent and young subject volumes were measured with an automated method. Results: We have observed that the young group was found to have a 4 % less in volume of GM, when compared with adolescent groups. Conclusion: Our data indicate that quantitative structural Magnetic Resonance Imaging (MRI) data of the adolescent brain is important in understanding the age-related human morphological changes.

Is the Age-Related Decline in Renal Function an Age-Associated Disease or Part of a Normal Aging Process?

Gerontology ◽  
2017 ◽  
Vol 63 (4) ◽  
pp. 325-326
Author(s):  
Fabian Braun ◽  
Paul Thomas Brinkkoetter
Keyword(s):  
Renal Function ◽  
Aging Process ◽  
Normal Aging ◽  
Age Related

Effects of Aging on Impairment Ratings: Part 1: Internal Medicine Issues

2018 ◽  
Vol 23 (5) ◽  
pp. 3-10
Author(s):  
Stephen L. Demeter
Keyword(s):  
Aging Process ◽  
Endocrine System ◽  
Normal Aging ◽  
Pulmonary System ◽  
Age Related ◽  
Metabolic Bone ◽  
Causative Factors ◽  
Impairment Ratings ◽  
Artery Disease ◽  
Effects Of Aging

Abstract This article is the first of four to explore the effects of age-related changes in impairment evaluations as defined by the fifth and sixth editions of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides). With respect to the cardiovascular system, impairment ratings for the following conditions commonly are affected by the aging process: coronary artery disease, valvular heart disease, arrhythmias/dysrhythmias, hypertension, and peripheral vascular disease. Impairment ratings in the fifth and sixth editions of the AMA Guides for the pulmonary system apply corrections for age with respect to certain measurements such as forced vital capacity. The normal aging process does not significantly affect impairment ratings for either hematological impairments or the endocrine system, nor does normal aging significantly affect the impairment ratings for mammary glands. With careful attention to the diagnosis and causative factors, evaluators may find that the normal aging process can affect impairment ratings associated with metabolic bone disease. Evaluating physician typically must determine impairment secondary to a specific cause (eg, injury or exposure) and therefore must consider if other factors are contributing to the impairment.

A common link between aging, schizophrenia, and autism?

2004 ◽  
Vol 27 (4) ◽  
pp. 593-594
Author(s):  
Jocelyn Faubert ◽  
Armando Bertone
Keyword(s):  
Nmda Receptor ◽  
Neurological Disorders ◽  
Aging Process ◽  
Normal Aging ◽  
Perceptual Processing ◽  
Compelling Evidence ◽  
Systematic Assessment ◽  
Age Related ◽  
Perceptual Functioning ◽  
Perceptual Performance

Phillips & Silverstein (P&S, 2003) have proposed that NMDA-receptor hypofunction is the central reason for impaired cognitive coordination and abnormal gestalt-like perceptual processing in schizophrenia. We suggest that this model may also be applicable to non-pathological (or normal) aging given the compelling evidence of NMDA-receptor involvement during the aging process that results in age-related change in higher-level perceptual performance. Given that such deficits are present in other neurological disorders such as autism, an argument for a systematic assessment of perceptual functioning in these conditions may be posited.

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