NEW
Cortical aging is layer-specific
Cortical degeneration is a hallmark feature of brain aging and associated with a number of everyday impairments. Here, we investigated whether aging homogeneously affects all cortical layers, or if some layers degenerate earlier than others. We investigated two cohorts of younger and older adults with 7T-MRI, and an aging mouse model with in-vivo 2-photon calcium imaging and histology, using SI as a model system. We demonstrate in humans that age-related cortical thinning is driven by deep layer thinning, whereas the middle and upper layers do not show signs of age-related degeneration. Instead, the input layer 4 is thicker and more myelinated in older compared to younger adults, and also more myelinated in older compared to younger mice. A case study with a person born without one arm revealed that layer 4 in the SI hand area contralateral compared to ipsilateral to the missing arm was thinner. Age-related increases in myelination are likely driven by a higher amount of inhibitory PV+ cells in the older mice. Taking these insights together, we present a new Layer Model of Sensory Aging that in our view will greatly influence the way we describe cortical aging in the future. Read the full article in Nature Neuroscience [link].
Cortical aging is layer-specific
Cortical degeneration is a hallmark feature of brain aging and associated with a number of everyday impairments. Here, we investigated whether aging homogeneously affects all cortical layers, or if some layers degenerate earlier than others. We investigated two cohorts of younger and older adults with 7T-MRI, and an aging mouse model with in-vivo 2-photon calcium imaging and histology, using SI as a model system. We demonstrate in humans that age-related cortical thinning is driven by deep layer thinning, whereas the middle and upper layers do not show signs of age-related degeneration. Instead, the input layer 4 is thicker and more myelinated in older compared to younger adults, and also more myelinated in older compared to younger mice. A case study with a person born without one arm revealed that layer 4 in the SI hand area contralateral compared to ipsilateral to the missing arm was thinner. Age-related increases in myelination are likely driven by a higher amount of inhibitory PV+ cells in the older mice. Taking these insights together, we present a new Layer Model of Sensory Aging that in our view will greatly influence the way we describe cortical aging in the future. Read the full article in Nature Neuroscience [link].
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INSIGHT
How the venous architecture influences cortical aging The cerebral vasculature contributes to cortical ageing, but its precise interaction with cortical microstructure is poorly understood. Our 7T-MRI study reveals lower quantitative T1 values (higher myelination) in older compared to younger adults in voxels that are closer to a vein. This effect was found in different areas of the cortex, including sensorimotor cortex. Our data provide evidence for a potential protective effect of the venous architecture on age-related cortical degeneration, and should be considered in neurobiological models of human brain organisation and cortical ageing. Read the full article: [link] CLINICAL APPLICATION
Multi-modal layer modeling reveals in vivo Pathology in ALS Amyotrophic Lateral Sclerosis (ALS) is a rapidly progressing neurodegenerative disease characterized by the degeneration of the motor system and the loss of motor control. We combined submillimeter structural 7 Tesla (7T) MRI data, functional localisers of body parts and automated layer modelling to create layer-specific in vivo pathology maps of MI in living ALS-patients with reference to age-, gender-, handedness- and education-matched controls. The pathology maps reveal a layer-specific profile of ALS pathology in MI, and uncover a potential role of low-myelin borders in the disease progression. A very-slow progressing patient shows a distinct pathology profile compared to the other patients. Our study shows that layer-specific markers of in-vivo pathology can be identified in ALS-patients with a single 7T-MRI measurement after first diagnosis, and that such data provide critical insights into the individual disease state. Read the full article: [link] |
+++ IN THE NEWS +++ Study finds touch-processing brain layers can strengthen as we get older (Listen to the CogniFit Podcast via Spotify) So schützen Sie das Gehirn vor dem Alterungsprozess (read the WELT article here) Part of your brain gets bigger as you get older - here is what that means for you (read the The Conversation article here) Großhirnrinde altert langsamer als gedacht - und steuert dem Altern entgegen (read MDR Wissen article here) Was haben ein Baum und unser (alterndes) Gehirn gemeinsam? (watch the Youtube video here posted by Uniklinik Tübingen) Wenn sich das Gehirn selbst zerstört Warum Altern glücklich macht Eingebrannt ins Gehirn Die Gene sind nicht alles - Was wir gegen Alzheimer tun können |
RESEARCH
Columnar Architecture within Cortical Field changes with Increasing Age
Shared response modeling (SRM) is a technique that allows group analyses by mapping individual stimulus-driven responses to a lower dimensional shared feature space. This can facilitate group analyses of ultra-high field imaging data, because no smoothing or normalization is required. In this 7T-fMRI study, we combine SRM with column-based decoding (C-SRM), and show that the number of columns that optimally describes finger maps in primary somatosensory cortex (SI) is higher in younger compared to older adults, indicating a greater columnar size in older adults’ SI. This provides first evidence that the columnar architecture of a functional area may change with increasing age. Read the full article: [link].
Columnar Architecture within Cortical Field changes with Increasing Age
Shared response modeling (SRM) is a technique that allows group analyses by mapping individual stimulus-driven responses to a lower dimensional shared feature space. This can facilitate group analyses of ultra-high field imaging data, because no smoothing or normalization is required. In this 7T-fMRI study, we combine SRM with column-based decoding (C-SRM), and show that the number of columns that optimally describes finger maps in primary somatosensory cortex (SI) is higher in younger compared to older adults, indicating a greater columnar size in older adults’ SI. This provides first evidence that the columnar architecture of a functional area may change with increasing age. Read the full article: [link].
RESEARCH
Layer-specific vulnerability is a Mechanism of Topographic Map Aging
Topographic maps form a critical feature of cortical organization, yet are poorly described with respect to their microstructure in the aging brain. Using parcellation-inspired techniques, we show that the output layer 5 of primary motor cortex (M1) shows a particular vulnerability to age-related increased iron, while layer 5 and the superficial layer show increased diamagnetic substance in older adults, likely reflecting calcifications. We provide a novel 3D model of M1 microstructure, where body parts form distinct structural units, but layers show specific vulnerability toward age-related degeneration. Our findings have implications for understanding basic principles of cortical aging. Read the full article: [link]
Layer-specific vulnerability is a Mechanism of Topographic Map Aging
Topographic maps form a critical feature of cortical organization, yet are poorly described with respect to their microstructure in the aging brain. Using parcellation-inspired techniques, we show that the output layer 5 of primary motor cortex (M1) shows a particular vulnerability to age-related increased iron, while layer 5 and the superficial layer show increased diamagnetic substance in older adults, likely reflecting calcifications. We provide a novel 3D model of M1 microstructure, where body parts form distinct structural units, but layers show specific vulnerability toward age-related degeneration. Our findings have implications for understanding basic principles of cortical aging. Read the full article: [link]
TOOL
Tongue Tracker (TT): A new automated tool to assess bulbar dysfunction in Older Adults & ALS patients
Bulbar symptoms, including difficulty swallowing and speaking, are common in amyotrophic lateral sclerosis (ALS) and other neurological disorders, such as stroke. We developed an open-source tool called Tongue Tracker (TT) to quantify bulbar function by training a neural network to track kinematic tongue features of short video clips of lateral tongue movements. We used TT to detect quantitative markers of bulbar dysfunction in ALS and older adults, and show that the method is sensitive to detect pathology-related alterations in bulbar function. Read the full article: [link]
Tongue Tracker (TT): A new automated tool to assess bulbar dysfunction in Older Adults & ALS patients
Bulbar symptoms, including difficulty swallowing and speaking, are common in amyotrophic lateral sclerosis (ALS) and other neurological disorders, such as stroke. We developed an open-source tool called Tongue Tracker (TT) to quantify bulbar function by training a neural network to track kinematic tongue features of short video clips of lateral tongue movements. We used TT to detect quantitative markers of bulbar dysfunction in ALS and older adults, and show that the method is sensitive to detect pathology-related alterations in bulbar function. Read the full article: [link]
RESEARCH
The Organizational Principles of 'de-differentiated' Topographic Maps
A common model of cortical aging assumes that more de-differentiated cortical maps link to worse everyday behavior. Using 7 Tesla MRI, we show that older adults' SI maps are not more de-differentiated then younger adults' maps when looking at standard markers of cortical de-differentiation. Rather, specific local and global map changes characterize aging topographic maps, where classical features of de-differentation link to better everyday behavior of the hand. We therefore introduce a new feature-based model of topographic map aging. Read the full article: [link]
The Organizational Principles of 'de-differentiated' Topographic Maps
A common model of cortical aging assumes that more de-differentiated cortical maps link to worse everyday behavior. Using 7 Tesla MRI, we show that older adults' SI maps are not more de-differentiated then younger adults' maps when looking at standard markers of cortical de-differentiation. Rather, specific local and global map changes characterize aging topographic maps, where classical features of de-differentation link to better everyday behavior of the hand. We therefore introduce a new feature-based model of topographic map aging. Read the full article: [link]
OHBM
See here Video presentations by Alicia Northall, Peng Liu and Juliane Doehler on human sensorimotor aging described with 7T-MRI
See here Video presentations by Alicia Northall, Peng Liu and Juliane Doehler on human sensorimotor aging described with 7T-MRI
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METHOD
Topographic layer imaging as a tool to track neurodegenerative disease spread in M1
One important feature that is often left out when diagnosing and analyzing disease spread in primary motor cortex (M1, for example in motor neuron disease) is the inhomogeneous architecture of M1 with respect to cortical layers but also topographic units. We therefore propose that combining 3D layer imaging with topographic mapping serves as ideal tool to understand which microstructural changes in M1 determine disease progression. Read the full article: [link]
Topographic layer imaging as a tool to track neurodegenerative disease spread in M1
One important feature that is often left out when diagnosing and analyzing disease spread in primary motor cortex (M1, for example in motor neuron disease) is the inhomogeneous architecture of M1 with respect to cortical layers but also topographic units. We therefore propose that combining 3D layer imaging with topographic mapping serves as ideal tool to understand which microstructural changes in M1 determine disease progression. Read the full article: [link]
RESEARCH
Impaired remapping of social relationships in older adults
Social relationships are a central aspect of our everyday life and are critical to maintain mental health. Yet, our ability to adapt to changes in social relationships as a consequence of changes in behavioral patterns is an under-investigated topic. In this paper, we combine VR with a social interaction paradigm and show that younger adults alter their behavioral pattern when an avatar changes its behavior (in the domains "power" and "affiliation"), whereas older adults show a reduction in such a "remapping" of social space. Our data provide first evidence that older adults have impaired abilities to "remap" the social space, similar to their impairments in remapping spatial environments during spatial navigation. Read the full article: [link]
Impaired remapping of social relationships in older adults
Social relationships are a central aspect of our everyday life and are critical to maintain mental health. Yet, our ability to adapt to changes in social relationships as a consequence of changes in behavioral patterns is an under-investigated topic. In this paper, we combine VR with a social interaction paradigm and show that younger adults alter their behavioral pattern when an avatar changes its behavior (in the domains "power" and "affiliation"), whereas older adults show a reduction in such a "remapping" of social space. Our data provide first evidence that older adults have impaired abilities to "remap" the social space, similar to their impairments in remapping spatial environments during spatial navigation. Read the full article: [link]
RESEARCH
Preserved body representations in advanced age
The rubber hand illusion is an often used paradigm to investigate multisensory body representations in health and disease, but it has rarely been investigated with respect to age-related changes in older adults. We show that there are no significant differences in explicit and implicit markers of the rubber hand illusion between younger adults (aged 20-30 years) and older adults (aged > 65 years). This indicates preserved pathways for establishing a multisensory representation of the bodily self in advanced age. Read the full article: [link]
Preserved body representations in advanced age
The rubber hand illusion is an often used paradigm to investigate multisensory body representations in health and disease, but it has rarely been investigated with respect to age-related changes in older adults. We show that there are no significant differences in explicit and implicit markers of the rubber hand illusion between younger adults (aged 20-30 years) and older adults (aged > 65 years). This indicates preserved pathways for establishing a multisensory representation of the bodily self in advanced age. Read the full article: [link]
CONCEPT
Changes in embodiment influence cognitive aging
Aging is associated with a number of deficits in sensorimotor and cognitive functions. We outline that a high number of age-related cognitive deficits arise from body-related processing differences. We propose a novel NFL-framework of bodily aging to conceptualize these changes. Key insight: Sensory and cognitive deficits on older age link to age-related changes in embodiment. Read the full articles: [link]
Changes in embodiment influence cognitive aging
Aging is associated with a number of deficits in sensorimotor and cognitive functions. We outline that a high number of age-related cognitive deficits arise from body-related processing differences. We propose a novel NFL-framework of bodily aging to conceptualize these changes. Key insight: Sensory and cognitive deficits on older age link to age-related changes in embodiment. Read the full articles: [link]
FUNDING
SFB-1436: Project B04 "Effects of hippocampal vascularization patterns on the neuronal resources of MTL neurocognitive circuits" (2020-2024)
DFG-Sachbeihilfe: "Cortical Microstructure & Aging" (2019-2023)
EKFS-Grant: "Topography and Plasticity of Cortical Microstructure in ALS characterized with 7T MRI" (2019-2023)
